Aspirin to prevent dvt

Sara Golieb’s Blood Clot Survival Story

I took what I thought was a routine flight to visit my family in Florida in October 2009. My leg had been bothering me a little before the flight, due to chronic Achilles tendonitis. When I got off the plane in Florida, my leg seemed stiffer than usual. The flight was uneventful, and since it was late when I got back to the house, I went right to bed.

The next morning, a pain shot up my leg from the sole of my foot when I stood and put weight on my leg. I had never felt pain like this in my foot or leg. I knew there was something wrong. I am 25 and in good shape, so even in my wildest dreams, I did not think my symptoms could be due to a blood clot. I limped around for three days in Florida and iced my leg, wrapped it in Ace bandages, and worried about the swelling.

I had never had that kind of swelling before. I should have listened to my gut, and asked my father to take me to the doctor right then. However, I felt silly about my worry, because of my Achilles tendonitis and my young age.

Three days after flying to Florida I returned home to Dallas. The pain was so bad that my mother would not let me go home. Mothers always know best. Luckily, I was able to get an appointment with a podiatrist the day after I returned. During the visit, the doctor could see the effect of the clot on my leg. My leg was swollen from the knee down and none of the new symptoms fit with the tendonitis. Just to be safe, he sent me for an ultrasound of my leg. Not five minutes after the ultrasound, the doctor paged me, and I was soon hearing those scary words, “You need to go to the nearest ER and tell them you have a blood clot in your leg.”

When I got to the ER, they wanted to do a repeat ultrasound to confirm the results of the first, because of potential side effects of treatment with “blood thinners.” This second ultrasound showed some relatively good news, even though I did not realize it at the time. The blood clot was in one of the smaller peripheral veins nearer to the skin surface, not in a deep vein. This is a thrombophlebitis rather than a DVT, so I was fortunate that it could be treated with aspirin.

I found out I could go home, start taking aspirin, and see a hematologist the next day. After high doses of aspirin, six follow-up visits for ultrasounds, blood tests to see whether I had a genetic clotting disorder, and discontinuation of my birth control pills, the superficial blood clot dissolved.

Even though all the tests have shown that I do not have a clotting disorder that predisposes me to clots, my life has changed forever. I make sure to drink a lot of water whenever I take a flight, and get up and walk around every 30 minutes while I am in the air.

I can never take birth control pills again and was told that if I get pregnant I will have to take a “blood thinner,” because changes during pregnancy make the blood clot more easily. I am going to have surgery to treat my tendonitis and my hematologist and orthopedic surgeon are going to put me on an injectable “blood thinner” for two weeks while my leg is immobilized.

I now try to live an even healthier and fulfilling life, and consult as needed with my primary care physician and a hematologist. I know I am lucky that I had an expert doctor who did not delay at all in sending me for that ultrasound just because I was young.
If you can learn anything from my story, please know that no matter how young you are you can get a blood clot. If you notice symptoms suggestive of a blood clot, such as leg swelling and pain, go to the doctor immediately. If you are contemplating use of birth control pills, make sure to discuss your family history (especially related to blood clots) as well as the adverse effects of birth control with your doctor. Take your life into your own hands.

Important Take Home Messages

Seek medical help immediately for swelling and pain in your leg.

Let your doctor know your family history of blood clots, particularly in your parents, sisters, or brothers.
Birth control pills increase risk of blood clots due to the effect or dose of hormones, either estrogen or progestin.
Blood clots can happen in young people.

Immobility and orthopedic surgery increase risk of blood clots.

Do heel-toe exercises while sitting on an airplane and get up and move around at least every hour, and drink plenty of water during the flight. This is true for car, train, and bus travel as well, especially when longer than 4 hours.

Thrombophlebitis (superficial vein thrombosis, or a clot in veins near the surface of the skin) is treated with some form of injectable heparin (or other “anti-clot” injectable medication) or a “blood thinner” in pill form for at least 4 weeks.

“Blood thinner” pills (typically warfarin) may be given on the same days (“overlapped”) as the injectable “anti-clot” medication for 5 days.

Oral or topical NSAIDs (non-steroidal anti-inflammatory drugs) may control symptoms in clots very near the skin surface without “blood thinners.”

Aspirin is not recommended as treatment for thrombophlebitis. Sara got better, but this was likely independent of the aspirin treatment.

This information describes what a blood clot is and how it’s treated.

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About Blood Clots

Normal blood clots form in blood vessels when a clump of platelets (a type of blood cell) come together to stop bleeding when you have a cut or an injury. When the cut or injury heals, your body will get rid of the blood clot. Blood clots can form anywhere in your body. Blood clots can also form in healthy blood vessels when they aren’t needed. This is called an abnormal (not normal) blood clot. Abnormal blood clots can lead to serious health problems.

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Types of Blood Clots

There are 2 types of blood clots that can be dangerous, deep vein thrombosis and pulmonary embolisms.

Deep vein thrombosis (DVT)

DVT can happen when an abnormal blood clot forms in a vein deep inside the body, usually in your arm or leg. The clot may affect your normal blood flow and cause swelling, redness, and pain in the area. If the clot isn’t treated, new blood clots may form, and it could break apart and spread to other parts of the body. These can make the swelling and pain worse and lead to trouble walking, an infection, or skin ulcers (sores).

Pulmonary embolism (PE)

A PE can happen when an abnormal blood clot blocks the flow of blood in a blood vessel in your lung. Most of the time, this happens when a blood clot in a deep vein of your leg breaks loose and travels to your lung. Having a PE can keep your body from getting enough oxygen.

If you have a PE, you may have:

  • Trouble breathing
  • Chest pain
  • A fast heartbeat
  • Pale or blue-colored skin

A PE can cause death if the signs aren’t treated quickly.

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Blood Clot Risk Factors

Some things can increase your risk of forming a blood clot. The risk factors include:

  • Not moving around often. This is because blood will flow slower in your deeps veins when you’re not moving, which can lead to a clot.
  • Having recently had surgery. This is because some surgeries may cause your blood to become thicker, or it may pool if you’re having a long surgery and not moving much.
  • Being injured
  • Having cancer

While you’re in the hospital, you may have more than 1 of these risk factors at the same time.

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Symptoms of Blood Clots

Blood clots can reduce the flow of blood throughout your body. Sometimes, people with a blood clot don’t feel any symptoms until the problem becomes life threatening.

Symptoms of these blood clots include:

  • Sudden pain and swelling in 1 arm or leg
  • Trouble walking due to swelling and pain
  • Sharp chest pain
  • Fast heartbeat
  • Trouble breathing
  • Severe abdominal (belly) pain with or without vomiting (throwing up) and diarrhea (loose or watery bowel movements)
  • Pale or blue-colored skin

Call your doctor right away if you notice any symptoms of a blood clot.

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Diagnosing Blood Clots

Since some people don’t have any symptoms of blood clots, many blood clots are found when your doctor is looking for something else, such as when you have a scan. Make sure you tell your doctor if you have any symptoms of a blood clot.

If your doctor thinks that you have a blood clot, they will recommend 1 or more of the following tests:

  • A computed tomography (CT) scan of your lungs to look for a PE. A CT scan takes x-ray pictures of your internal organs.
  • An ultrasound of your veins to look for blood clots in your legs or arms. The ultrasound machine uses sound waves to create pictures of the inside of your body.
  • Blood tests to measure how quickly your blood clots. Blood tests can also see if you have any genes that may increase your risk blood clots.

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Treating Blood Clots

Treatment for a blood clot usually includes taking a blood thinner, also known as an anticoagulant. This is the most common treatment for blood clots. Blood thinners help prevent your body from making new clots.:

Blood thinners can be given:

Your doctor will decide which type of medication is best for you.

How long you’ll need to take blood thinners depends on many factors. Your doctor will consider your risk factors and will help decide how long you need to take them. Some people may need to stay on them forever. You’ll have regular visits with your doctor while you’re on blood thinners.

Some blood thinners may have special instructions, such as medications you’ll need to avoid while you’re taking them. If you’re taking a blood thinner with any special instructions, your doctor will go over them with you.

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Preventing Blood Clots

There are many things you can do to prevent blood clots from forming. The following are ways to prevent blood clots.

Physical activity

Staying active is a good way to prevent blood clots. Mild or moderate exercise, such as walking, or yoga can improve your blood flow. Try to move every few hours, if you’re able to, as instructed by your doctor. For most people, this means as much as you feel comfortable with.

It’s also important to move often if you’re sitting for long periods of time, such as while traveling on a plane or in a car. If you’re unable to get out to walk around, be sure to change positions often while on a long trip.

If you’re not able to move around easily, try doing some light stretches and movements with your feet, if you’re able. You can make circles with your feet or point your toes up and down while you’re sitting or lying down.


If your healthcare provider prescribed you anticoagulation medication (blood thinners), be sure to take your medication as instructed. This medication will reduce the chance of a blood clot forming.

Sequential compression device (SCD) sleeves

If you’re in the hospital, your risk of getting a blood clot is higher. To help prevent a blood clot, you can use SCD sleeves. SCDs are sleeves that wrap around your lower legs. The sleeves are connected by tubes to a machine that pushes air in and out of the sleeves to gently squeeze your legs. This is a safe and effective way to help your blood circulate (move around) to prevent clots.

You should always wear the SCD sleeves when you’re in your hospital bed, unless you’re told not to by your healthcare provider. Make sure you remove the SCD sleeves before getting out of bed because the tubing could make you trip and fall. Tell your healthcare provider if you notice the tubing is pinched or the pump is beeping.

Other tips to prevent blood clots

You can also help prevent blood clots by following these tips:

  • Wear loose-fitting clothes, socks, or stockings.
  • If your doctor recommends them, wear compression stockings. These are special stockings that can improve your blood flow.
  • Avoid crossing your legs while sitting.
  • Raise the bottom of your bed 4 to 6 inches with blocks or books. This will help elevate your legs to improve your blood flow.
  • Eat less salt. Eating too much salt may cause swelling and can increase your risk of getting a blood clot.

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Call Your Doctor or Nurse if You Have:

  • Increased pain, swelling, or both in the arm or leg with the blood clot
  • New pain, swelling, or both in your other arm or leg
  • Trouble breathing
  • Severe headaches or headaches that don’t go away
  • Nose bleeds
  • Bleeding gums
  • Blood in your urine (pee), stool (poop), vomit, or in the mucus that you cough up through your mouth
  • A heavier menstrual flow (period) than usual
  • Bleeding that doesn’t stop
  • Bruising that doesn’t go away
  • Fallen or hurt yourself in any way
  • Plans for any dental procedure or surgery
  • Stopped taking your blood thinner for any reason
  • Any unexpected, unexplained side effects
  • Any questions or concerns

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An Aspirin a Day May Not Keep DVT Away

Aspirin has been used for decades to treat health problems ranging from the common headache and arthritis to fever and toothaches, and for the prevention of heart attacks. Aspirin therapy works by helping the body reduce pain, fever, swelling, and to prevent the formation of specific types of blood clots. In fact, it can be used to prevent blood clots that flow to the brain and cause certain types of stroke.

The American Heart Association recommends aspirin therapy to prevent a recurrence of heart attacks, recurring angina, and second strokes. But when it comes to deep vein thrombosis (DVT), a condition in which a clot forms in a deep vein, typically in your leg or pelvic area, there is controversy about the usefulness of aspirin therapy.

Aspirin Therapy and DVT

“Aspirin therapy has virtually no role to play in the treatment of deep vein thrombosis or the prevention,” says Jack Ansell, MD, chairman of the department of medicine at Lenox Hill Hospital in New York City. “Aspirin interferes with arterial platelet aggregation , which has major important effects in cardiovascular circulation. But for DVT, there is no case in which it is appropriate.”

DVT Prevention: Aspirin Therapy During Surgery

Dr. Ansell says that a number of orthopedic surgeons believe that, during surgery for hip or knee replacements, aspirin therapy can prevent dangerous blood clots that cause DVT. “A good number of surgeons still use aspirin, even when there is a major debate among physicians as to how effective it is. But most experts will not agree that it’s effective or appropriate.”

The American Academy of Orthopaedic Surgeons (AAOS) has pre- and post-surgical guidelines that are designed to prevent pulmonary embolism, a sometimes fatal condition in which a blood clot caused by DVT breaks free and travels to the lungs.

The AAOS guidelines say that in the case of a total joint arthroplasty, in which a joint is replaced, an orthopedic surgeon may use three treatment options to help prevent a pulmonary embolism:

  • The blood thinner warfarin (Coumadin and others)
  • Aspirin
  • A mechanized treatment for blood clots in which a sleeve-like device regularly compresses the legs during and after surgery to keep the blood flowing

Aspirin Therapy and DVT: The Debate

A recent study on this topic was presented at an AAOS meeting in which researchers examined data from more than 93,840 patients who had undergone knee replacement surgery. They compared the risk of pulmonary embolism, death, surgical site bleeding, and infections in patients who received aspirin and with patients who were given other therapies.

The number of blood clots that developed in the lungs of patients who took aspirin was the same as for those who took warfarin, which is injected. However, patients who took aspirin may have been less at risk for blood clots in the first place.

Is this enough evidence to use aspirin as a DVT treatment? Not according to Ansell, the AAOS, and the American College of Chest Physicians, who believe that heparin, low-molecular-weight heparin (LMWH), or warfarin should be used before joint replacement surgery to prevent both DVT and pulmonary embolism. There is no clear evidence that aspirin can help to prevent most cases of blood clots, says Ansell.

Aspirin is also not a means for preventing DVT in people who sit motionless while traveling long distances. The best way to prevent DVT when sitting for long periods is to get up and walk around as much as possible when on an airplane and to stop every few hours and stretch your legs when driving long distances.

Aspirin Therapy: What It Helps

Since aspirin reduces the ability of bloods platelets to stick to each other, it’s often prescribed to those not only at risk of a clot-related stroke, but also for those who have certain blood vessel diseases.

But you need to avoid aspirin if you have the following conditions:

  • Pregnancy, unless prescribed by your doctor
  • High blood pressure
  • Bleeding disorders
  • Asthma, in some cases
  • Aspirin allergy or sensitivity

Side effects of aspirin therapy include increased risk of stomach bleeding and kidney failure.

If you’re worried about DVT, talk to your doctor about your individual risk factors and the things you can do to minimize those risks.

‘Economy class’ DVT syndrome myth busted

“Sitting in a window seat during a long flight can increase the risk of deep vein thrombosis,” according to The Daily Telegraph. It has long been known that flying is associated with an increased risk of deep vein thrombosis (DVT), a type of serious blood clot in a major vein, but new US guidance has looked at a range of factors that could potentially raise the risk.

Those of you thinking of booking your summer holiday might be interested to know that flying in cramped budget seats, while often annoying, presented no greater risk than flying in business class. And while pricey booze available during a flight can prove wallet-damaging, the guidelines say there was no firm evidence that drinking it could bring on DVT. However, sitting by a window during a long-haul flight was associated with a greater risk because of the limited opportunities for walking around. People’s age, previous DVT and recent operations were among the other factors found to raise DVT risk.

The evidence-based guidelines were produced by the American College of Chest Physicians to address the risk of both DVT after long-haul flights and the potentially fatal lung clots (pulmonary embolisms) that can follow. The guidelines also include recommendations about the best ways for travellers to reduce their risk of DVT.

The guidelines seem to debunk the long-held assumption that a lack of legroom causes DVT. This much-debated phenomenon is often referred to as “economy-class syndrome”.

What is “economy-class syndrome”?

It is long established that inactivity is associated with DVT, and so some people believe that the lack of legroom when flying in economy class can increase the risk of developing a blood clot. This has led to the theoretical phenomenon being dubbed “economy-class syndrome”.

Some have also suggested that dehydration is more common during economy travel and may increase the risk of DVT. However, the existence of this so-called “economy-class syndrome” is controversial and has never been proven.

What is DVT?

Deep vein thrombosis or DVT is when blood clots form in a deep vein. A clot that develops in a vein is also known as ‘venous thrombosis’. DVT most commonly affects the leg veins or deep veins in the pelvis. It can cause pain and swelling in the leg but in some cases there may be no symptoms.

DVT can lead to the potentially life-threatening condition known as a pulmonary embolism. This occurs when a clot breaks off into the bloodstream and travels to the chest, where it blocks one of the blood vessels in the lungs.

Experiencing DVT and pulmonary embolism together is known as venous thromboembolism (VTE), which is a condition that can be life-threatening. Each year more than 25,000 people in England die from VTE contracted in hospital. This is approximately 25 times the number of people who die from MRSA. VTE occurs in hospitals as a result of patients lying sedentary in bed for extended periods following an operation. In recent years the NHS and Department of Health have run a major programme of measures to help reduce the rates of VTE developed in hospitals. For example, many patients are now given a VTE risk assessment when being booked into hospital.

Who is at risk of DVT?

In the UK each year about one person in every 1,000 is affected by DVT. Anyone can develop it but there are certain known risk factors that include:

  • increasing age
  • pregnancy
  • previous venous thromboembolism
  • family history of thrombosis
  • medical conditions such as cancer and heart failure
  • inactivity (for example after an operation or on a long-haul flight)
  • being overweight or obese

Where has the advice come from?

The advice comes from new evidence-based guidelines produced by the American College of Chest Physicians (ACCP). The findings were published in the February issue of the medical journal CHEST.

The guidelines are extensive, running over hundreds of pages. They detail both the risk factors for DVT and measures to diagnose and prevent DVT.

What do these guidelines tell us?

The evidence review that informed the guidelines looked at a range of risk factors for the development of DVT in long-distance travellers. These included the use of oral contraceptives, sitting in a window seat, advanced age, dehydration, alcohol intake, pregnancy and sitting in an economy seat compared to business class.

The reviewers conclude that developing DVT or pulmonary embolism from a long-distance flight is generally unlikely, but that the following factors increased people’s risk:

  • previous DVT or pulmonary embolism or known ‘thrombophilic disorder’
  • cancer
  • recent surgery or trauma
  • immobility
  • advanced age
  • oestrogen use, including oral contraceptives
  • pregnancy
  • sitting in a window seat
  • obesity

The finding relating to window seats was discussed further. The study authors suggest that long-distance travellers sitting in a window seat tend to have limited mobility, which is responsible for their increased risk of DVT.

However, the review did not find any definitive evidence to support the theory that dehydration, alcohol intake or sitting in an economy seat (compared with sitting in business class) increases the risk of DVT or pulmonary embolism during a long-distance flight. On this basis, they conclude that travelling in economy class does not increase the risk of developing a blood clot, even during long-distance travel. However, they believe that remaining immobile for long periods of time does.

Overall, the study authors say that “symptomatic DVT/PE is rare in passengers who have returned from long flights”, but that the association between air travel and DVT/PE is strongest for flights longer than 8-10 hours. Furthermore, most of the passengers who do end up developing a DVT/PE after long-distance travel have one or more risk factors.

What can be done to prevent DVT?

For travellers on flights longer than six hours who have an increased risk of DVT the new guidelines recommend:

  • Frequent walking about during the flight.
  • Calf muscle stretching.
  • Sitting in an aisle seat if possible (as you are more likely to get up and move around during the flight).
  • Wearing below-the-knee compression stockings that are ‘graduated’, meaning they apply greater pressure lower down the leg. They are designed to put pressure on the lower legs, feet and ankles to increase bloodflow, thereby making it harder for a clot to form.

The guidelines do not recommend compression stockings for long-distance travellers who are not at increased risk of DVT.

The guidelines advise against using blood-thinning aspirin or anticoagulant therapy to prevent DVT or pulmonary embolism for most people. They suggest that anti-clotting medications should be considered on an individual basis only for those at particularly high risk of DVT, as in some cases the risks may outweigh the benefits.

Analysis by Bazian
Edited by NHS Website

Links to the headlines

DVT risk raised by sitting in the window seat

The Daily Telegraph, 7 February 2012

Dangers of DVT: Why you should avoid the window seat on the plane (even in First Class)

Daily Mail, 7 February 2012

Links to the science

Bates SM, Jaeschke R, Stevens SM, et al.

Diagnosis of DVT : Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

Chest 2012;141;e351S-e418S. Published online February 7 2012

Air travel health tips

Updated: January 20, 2017Published: September, 2005

With summer’s approach come plans for travel, including flying long distances. But the prospect of a long flight often raises health concerns. Especially in passengers who are older or have certain conditions, air travel and the related stress can have an impact on health. Here are a few trouble areas and some precautions you can take.

Deep-vein thrombosis (DVT). Not all experts agree on an association between DVT (blood clots in the legs) and air travel. Symptoms may not occur for several days, so it’s difficult to establish a cause-and-effect relationship. If there is one, it’s likely due to prolonged inactivity. Limited airline space can discourage moving about. Dry cabin air may also increase the risk of DVT.

Prolonged inactivity slows circulation, allowing small clots to form in the legs and feet. The body’s own clot busters kick in for most people, but in people with certain risk factors, the clots can get big enough to block a vein. These include cancer, heart disease, infection, pregnancy, and obesity, as well as recent injury or surgery. Smoking also raises the risk, as do birth control pills, selective estrogen receptor modulators, and postmenopausal hormones.

DVT in the calf aches and gets worse over several days. The pain may be accompanied by warmth and swelling in the area around or below the clot. A clot in the thigh or at the juncture of the thigh and abdomen causes similar symptoms. The skin may redden or turn bluish. If you experience any of these symptoms, see a doctor; be sure to mention that you’ve recently traveled on a plane.

The biggest danger of DVT is that a clot will break free and lodge in one of the pulmonary arteries supplying blood to the lungs. This potentially fatal condition is called pulmonary embolism. Symptoms include rapid breathing, pain when breathing, shortness of breath, chest pain that travels up to the shoulder, fever, and fainting. It is a medical emergency. Air travelers can do several things to reduce their risk:

  • If you’re not at risk for bleeding and can tolerate aspirin, take a baby aspirin (81 milligrams) one-half hour before takeoff.
  • Wear loose clothing and comfortable shoes.
  • Avoid crossing your legs while seated.
  • Get up from your seat and walk up and down the aisle at least once an hour. If you’re pregnant, request an aisle seat so that you can get up easily.
  • Drink at least 8 ounces of water every hour or two and avoid alcohol, caffeinated beverages, and salty foods.
  • Keep the space under the seat in front of you empty so you can exercise your feet and ankles occasionally.
  • If you have any risk factors for deep-vein blood clots, consult your clinician. She or he may suggest support socks or stockings.

Reduced oxygen and air pressure. At cruising altitude, airline cabins have lower-than-normal air pressure and oxygen levels. Blood oxygen saturation during commercial flights can be 5%–10% lower than normal. If you’re in good health, your body can compensate, but if you have a lung condition, such as chronic obstructive pulmonary disease, or cardiovascular disease, you may need supplemental oxygen, even if you don’t normally use it. Ask your physician for advice several weeks before your flight.

If you need oxygen, call your airline to find out its policies and the cost. Airlines generally require advance notice, and the FAA doesn’t allow passengers to bring their own oxygen supply on commercial aircraft. Most airlines require a letter on your doctor’s letterhead confirming your need for supplemental oxygen while flying, along with the required oxygen flow rate. You’ll need a copy for every flight segment. Airline charges for oxygen range widely.

Ear pain. During takeoff and landing, cabin air pressure changes rapidly, disturbing the balance of pressure between the outer ear and the middle ear. Many people feel pain when the higher pressure stretches the eardrum, the membrane separating the outer and middle ears.

The Eustachian tube, which connects the middle ear to the back of the nose and throat, helps equalize the pressure on the eardrum (and causes the welcome pop you feel when the balance is restored). You can help the process by swallowing, chewing gum, yawning, or opening your mouth wide. A trick called the Valsalva maneuver may also work: Close your nose with your thumb and index finger and exhale gently against a closed mouth.

Jet lag. Crossing time zones often leads to jet lag, which can result in headaches, upset stomach and nausea, difficulty concentrating, and trouble sleeping. To help alleviate it, get plenty of sleep before you begin your trip. Keep well hydrated before, during, and after your flight. Change your wristwatch to the new time. As soon as you arrive at your destination, adjust your sleeping and eating schedule to the new time zone. This can be difficult if you’ve crossed many time zones, but try to force yourself to stay awake until the local bedtime, and get up in the morning when the locals do and get outside in the natural light. If you simply cannot stay awake until evening on the day you arrive, nap for no more than an hour or two. Engaging in social activities can also help your body clock adjust. When trying to stay awake, eat protein and vegetables and avoid starchy foods like pastas, breads, and rice.

As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.

Aspirin and Blood Clots

What is the Role of Aspirin in Preventing Recurrent Venous Thromboembolism?

For several decades, aspirin has been the mainstay of antithrombotic therapy to prevent recurrent arterial thrombotic events. Aspirin is also effective in the primary prevention of myocardial infarction, particularly in men. For the prevention of deep venous thrombosis and pulmonary embolism, anticoagulants are the antithrombotic agents of choice; the vitamin K antagonist warfarin is highly effective for the prevention of venous thromboembolism in patients at high recurrence risk. Warfarin however carries a significant risk of major hemorrhage and requires regular laboratory monitoring of the International Normalized Ratio (INR) and dosage adjustments; it also is subject to food and medication interactions. While there is data that aspirin may have modest efficacy in the primary prevention of venous thromboembolism in orthopedic surgical patients, parenteral agents (particularly the low molecular weight heparins) have been the agents of choice for high-risk surgical patients.

In the last year, two clinical trials with similar design have been published in the New England Journal of Medicine evaluating the efficacy of low-dose aspirin versus placebo in preventing venous thromboembolism. These studies included patients with a first episode of unprovoked venous thromboembolism who were treated with anticoagulation for 3-6 months; this patient population is felt by many to be in “equipoise” regarding the benefits of extending warfarin therapy beyond this time interval given its hemorrhagic Center in Boston, MA potential. Given the relative safety of aspirin with respect to bleeding and its ease of use, it was hypothesized that it could be an attractive option in this patient population. A pooled analysis of the data in the two studies showed that 100 mg of aspirin daily resulted in approximately a 30% risk reduction in recurrent venous thromboembolism with no increase in bleeding; this is to be contrasted to a greater than 90% risk reduction with warfarin at an INR intensity of 2-3. While these methodologically rigorous studies provide data that aspirin can prevent venous thrombotic events, its efficacy is modest compared to an anticoagulant.

How should this information be used in managing patients with unprovoked venous thromboembolism at risk for recurrent venous thromboembolism? Deciding whether to continue anticoagulation with warfarin after initial treatment of acute VTE requires an individual assessment of risks of recurrence and bleeding as well as patient preference. Those believed to have a higher risk of recurrence or have more severe consequences of recurrence are likely to derive increased benefit from anticoagulation. Patients with perceived low to moderate risk of recurrence who desire some protection may benefit from the modest 30% risk reduction conferred by aspirin with little impact on lifestyle and minimal medication cost.

The new oral anticoagulants that target thrombin or factor Xa (dabigatran etexilate, rivaroxaban and apixaban) have been evaluated for the prevention of recurrent venous thromboembolism. Rivaroxaban recently became the first novel anticoagulant approved for this indication in the US and Europe. Rivaroxaban was compared with placebo and was more effective for extended VTE treatment, albeit with more bleeding. A trial of apixaban at a dose of 2.5 mg or 5 mg twice daily versus placebo for 12 months showed very low recurrence rates for both doses of the drug and low bleeding rates that were not statistically different than placebo.
Ken Bauer, MD, Chief
Hematology Section, VA Boston Healthcare System and Director, Thrombosis Clinical Research, Beth Israel Deaconess Medical

1. Becattini C, Agnelli G, Schenone A, et al. Aspirin for preventing the recurrence of venous
thromboembolism. N Eng J Med 2012; 366:1959-1967.

Ken Bauer MD, is a member of the Medical and Scientific Advisory Board of the National Blood
Clot Alliance.

March 2013

Aspirin may prevent blood clots in the legs from recurring

Published: February, 2013

People who develop blood clots in their legs—a condition called venous thromboembolism—must take warfarin (Coumadin) for several months or longer to prevent another clot from forming and possibly traveling to the lungs, with deadly results. Yet warfarin can cause unwanted bleeding and requires regular blood testing. As a result, no one wants to be on this treatment forever. The question is, what else might they do to reduce their risk for another blood clot if they stop taking warfarin?

Now the combined results of two compatible studies have determined that a low dose of aspirin (100 mg per day) may be an effective substitute for long-term use of warfarin. Both studies examined people who had developed a clot in the legs for unknown reasons. In both studies, the clots were dissolved with heparin, and treatment with warfarin followed for up to three months. Then warfarin was discontinued, and the study participants were given either daily low-dose aspirin or placebo (sugar pill). Compared with placebo, aspirin reduced the rate of recurrent clots by one-third, and helped prevent strokes, heart attacks, and other undesirable consequences, with a very low risk of bleeding. The researchers concluded that low-dose aspirin would be a reasonable option for long-term clot prevention in people who suffer a first clot for unknown reasons.

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Air Travel and Venous Thrombosis: How Much Help Might Aspirin Be?

Abstract and Introduction

There has been considerable attention focused recently on the risk of deep venous thrombosis (DVT) associated with air travel. Despite the lack of evidence among air travelers, a single dose of aspirin has been widely recommended as a means of preventing such thrombosis. We have calculated the potential benefit of aspirin by applying the data for aspirin in preventing DVT in hip fracture patients to the estimated rates of travel-related DVT. If the rate of travel-related DVT is 20 per 100,000 travelers, then we will have to treat 17,000 people with aspirin to prevent 1 additional DVT.

Following a spate of media reports highlighting the risk of DVT in air travelers, a number of patients have come to your clinic to seek advice on the potential benefits of taking aspirin prior to their journey.

Case Scenario 1: A fit and healthy 23-year-old male medical student is flying out to a distant country for his elective medical attachment. He wonders if he should take a tablet of aspirin prior to his intercontinental flight.

Case Scenarios 2 and 3: A husband and wife are planning a round-the-world trip to celebrate their 25th wedding anniversary. The husband is a normotensive 60-year-old smoker (case 2) and the wife is a healthy 52-year-old nonsmoker (case 3). They have seen newspaper reports that aspirin can help prevent travel thrombosis and would like guidance from a medical practitioner on the value of aspirin.

In the above situations, what evidence-based advice should a physician give?

Much has been written in recent months about the potential risk of DVT with air travel and the measures that could be taken to reduce this risk. In addressing this, a British Government Report recommended that travelers at moderate risk should seek the advice of their doctors on the use of preflight low-dose aspirin. Unfortunately, this advice has been difficult to provide, first because there are insufficient data available for physicians to be able to predict accurately the absolute risk of DVT in specific individuals, and second because there is a complete absence of evidence on the efficacy of aspirin in long-distance travel.

For the patient, postponing this treatment decision until better data become available (in some years), is not an option. In real-life clinical practice, a decision will need to be made there and then, even if the best we can manage is an “educated guess.” We have made a projection from existing data of what benefit aspirin might confer, and hope this will help to guide doctors and patients in making therapeutic decisions until more definitive evidence becomes available.

(image: Rex Parker)

Among people with unprovoked deep venous thrombosis (DVT) or pulmonary embolism (PE), 1 in 5 will experience another DVT or PE within 2 years after stopping anticoagulation with warfarin (Coumadin). For this reason, the ACCP’s recommendations for treatment of unprovoked proximal DVT or PE suggest consideration of an “indefinite” period of anticoagulation — a soft way of saying “lifelong.” That’s a burdensome prescription, committing patients to the continual elevated risk of bleeding and a requirement for periodic monitoring with blood draws or finger-sticks.

New anticoagulants rivaroxaban (Xarelto) and dabigatran (Pradaxa) may eventually become standard-of-care alternatives for long-term anticoagulation to reduce risk for recurrent DVT or PE. But these drugs are expensive, and their full, real-world safety profiles will have to emerge over time.

What about good old fashioned aspirin? In a randomized trial published in the May 24 New England Journal of Medicine, a single daily 100 mg aspirin, begun after completing 6-18 months of warfarin, reduced the risk of recurrent venous thromboembolism (VTE) by an impressive 40% compared to placebo.

What They Did

Cecilia Becattini, Giancarlo Agnelli, Paolo Prandoni et al (the WARFASA investigators) randomized 402 patients with an unprovoked DVT or PE to begin taking aspirin 100 mg daily or placebo for 2 years, after completing 6-18 months of warfarin therapy.

Primary outcomes were symptomatic recurrent DVT or PE, and major bleeding (defined as either being in a critical location like intracranial, or >= 2 g/dL drop in hemoglobin, or >= 2 units transfused).

Patients were ~62 years old. 34-40% of the patients had had pulmonary embolism as their VTE; 60-66% had had deep venous thrombosis. More people in the group randomized to aspirin had had first PEs (34 vs. 40%). Most (>50%) had been treated with warfarin for at least 12 months; about one-third in each group had only been treated for 6 months. Patients randomized to placebo had been treated with warfarin for slightly longer as a group (a priori, this should have biased toward the null and made a positive result for aspirin harder to achieve).

What They Found

Aspirin reduced the risk of recurrent VTE by a relative 42%, and by an absolute 5% — a number needed to treat of less than 20 to prevent one recurrent episode of venous thromboembolism with daily aspirin.

The numbers broke down as follows:

  • There were 71 total recurrent VTEs among 403 patients (8.6% per year). 27 were recurrent PEs and 44 were recurrent DVTs.
  • 28 of 205 patients taking aspirin had recurrent DVT or PE (6.6% per year)
  • 43 of 197 patients taking placebo had recurrent DVT or PE (11.2% per year)
  • 11 of 83 taking aspirin for previous PE had a recurrent pulmonary embolism (6.7%), compared to 16 of 67 placebo-taking patients (13.5%).

This last figure — potentially the most important — suggests daily aspirin provides an absolute ~7% risk reduction (60% relative risk reduction) for recurrent pulmonary embolism after a first PE that was properly treated with warfarin. That’s a number needed to treat of only 15 to prevent a symptomatic pulmonary embolism with daily aspirin. (I know, this wasn’t a prespecified endpoint … but it’s impressive nonetheless, to me.)

The new anticoagulants dabigatran (Pradaxa) and rivaroxaban (Xarelto), by comparison, reduced risk by more than a relative 80% in clinical trials. Low-intensity warfarin is believed to provide a ~65% relative risk reduction.

There was one episode of major (nonfatal) bleeding in the placebo group, due to a gastric ulcer, and one in the aspirin-treated group, due to bowel angiodysplasia.

Authors report their study was funded by their home institution of University of Perugia (Italy), and by a “grant-in-aid” from Bayer HealthCare (makers of rivaroxaban/Xarelto, and of course Aspirin®), and Aventis (who help fund Dr. Becattini through a fellowship).

Clinical Takeaway: With the new anticoagulants poised to dislodge warfarin as first-line treatment for a first DVT or PE, and this study suggesting aspirin as a reasonable option for “indefinite” secondary prevention after a first unprovoked DVT or PE, it looks like warfarin’s days as the treatment for venous thromboembolism may be numbered.

Becattini C et al (WARFASA Investigators). Aspirin for Preventing the Recurrence of Venous Thromboembolism. N Engl J Med 2012;366:1959-1967.

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An Aspirin a Day to Keep the Clots Away

Patients presenting with deep vein thrombosis (DVT) in the absence of any identifiable risk factors are said to have an unprovoked or idiopathic DVT. Recurrent events are much more common in these patients (10% versus ≤ 3% at 1 year) compared with patients with a DVT provoked by a reversible risk factor, and such events represent a major healthcare problem.1 Three months of anticoagulation is sufficient to decrease the risk of recurrent thrombosis related to the initial DVT. However, once therapy is discontinued, the risk for recurrence rises dramatically. It has been suggested that 30% to 50% of patients experience a recurrence at 10 years.2,3 Factors associated with a higher likelihood of recurrence are male sex, elevated D dimer, incomplete resolution of DVT, body mass index ≥30, and post-thrombotic syndrome.4 In fact, a number of tools have been developed to determine the risk of recurrence after DVT.

Article see p 1062

In the current management paradigm, patients with unprovoked DVT are evaluated for long-term anticoagulation after initial treatment with 3 to 6 months of anticoagulation. The risks of major bleeding during prolonged therapy are periodically weighed against the benefits of continuing anticoagulation in high-risk patients. Data supporting this approach come from 4 studies demonstrating a decrease in recurrent venous thromboembolism (VTE) by 90% with extended conventional dose vitamin K antagonists (VKA) therapy.5 Major bleeding occurs in 20 per 1000 patients, and as of yet no validated prediction tool exists to predict risk–benefit ratio of extended therapy.6 Factors associated with an increased risk of bleeding include advanced age >75 years, history of gastrointestinal bleeding, noncardioembolic stroke, renal or hepatic disease, concomitant antiplatelet usage, and poor control of anticoagulation.5 In the interest of diminishing the bleeding risk while conferring protection against recurrent venous thromboembolism several approaches have been taken: subtherapeutic anticoagulation with VKA, new oral anticoagulant agents, and aspirin.7

Two trials randomized patients after completing fully VKA anticoagulation (3–6 months) to either placebo or sub therapeutic VKA therapy (target international normalized ratio of 1.5–1.9). Patients receiving indefinite sub therapeutic anticoagulation had a 62% to 64% relative risk reduction of recurrent VTE.7,8 Although low-intensity VKA was more effective than placebo, it was less efficacious than full-dose VKA. Use of a lower international normalized ratio target did not decrease the number of clinically important bleeding events, dampening overall enthusiasm for this approach.8

New oral anticoagulants (NOACs) which do not require monitoring nor dosage adjustment have emerged as a convenient alternative for long-term prevention of recurrent VTE. To date, 3 trials have evaluated NOACs against placebo for an additional 12 months of therapy beyond initial anticoagulation9–11 (Table). In a pooled meta-analysis of the data, NOACs decreased the risk of recurrent VTE or VTE-related death by 84% with a number needed to treat of 17 compared with placebo.12 However, bleeding remained a significant source of morbidity with a higher risk of major or clinically relevant bleeding (4.6% versus 2.0%; odds ratio, 2.69; 95% confidence interval, 1.25–5.77) in the NOAC group and a number needed to harm of 39.12 One trial has evaluated dabigatran compared with warfarin for the extended treatment of VTE. In this trial, patients were randomized to either dabigatran 150 mg twice daily or warfarin (with a goal international normalized ratio of 2.0–3.0) for 12 months after completion of acute anticoagulation. The primary end point of symptomatic DVT, fatal pulmonary embolism, and all-cause mortality was similar between the 2 groups. A lesser risk of major bleeding (5.6% versus 10.2%, P<0.001) was offset by the increased incidence of acute coronary syndrome in the dabigatran group (0.9% versus 0.2%, P=0.02).9 The expense and lack of any commonly available reversal agents represent drawbacks to the use of NOACs.

ASA indicates aspirin; CI, confidence interval; HR, hazard ratio; INR, international normalized ratio; NOAC, new oral anticoagulant; VKA, vitamin K antagonist; and VTE, venous thromboembolism.

*At minimum 1 y (range 12–48 mo) of follow up; compared with placebo.

†73% to 93% of patients with unprovoked VTE.

Despite universal availability, inexpensive cost, and well-established drug safety profile, the use of aspirin previously has not been extensively studied outside of the orthopedic surgery population for the treatment or prevention of VTE. Practically, aspirin may represent a convenient intermediate therapy between no treatment and indefinite anticoagulation, balancing the risk of bleeding with the benefit of preventing recurrent thrombosis in a moderate risk population. Two trials recently were completed to address this question: the Warfarin and Aspirin (WARFASA) study13 and the Aspirin to Prevent Recurrent Venous Thromboembolism (ASPIRE) study.14 In both trials, aspirin was compared against placebo after completion of a minimum of 6 weeks of anticoagulation in patients with unprovoked VTE. Patients were treated with 100 mg of aspirin or placebo for 2 to 4 years. In both trials a decrease in recurrent VTE was demonstrated with a low risk of major bleeding. However, neither study was powered to detect moderate treatment effects among different subgroups of patients.

The Aspirin for the prevention of recurrent venous thromboembolism study (INSPIRE)15 was designed to more accurately delineate the treatment effects of the WARFASA and ASPIRE trials in prespecified subgroups by combining the results at a patient level before unblinding of the 2 arms. The study was initially powered to detect with 80% confidence a 30% reduction in recurrent VTE, although as a result of slow enrollment was ultimately powered to detect a 35% reduction in recurrent VTE. VTE occurred in 18.4% of patients on placebo and in 13.1% of patients assigned to aspirin (hazard ratio, 0.68; 95% confidence interval, 0.51–0.90; P=0.008) corresponding to a number needed to treat of 42 to prevent 1 symptomatic VTE occurrence. Additional data garnered from this analysis were most valuable in identifying the populations most likely to benefit (men and individuals aged ≥65 years) and evaluating the treatment effect over time. The absolute reduction of recurrent events was significantly greater over the first year when the risk of recurrence was highest.

It is surprising, given that platelets are known to be central to thrombosis, that antiplatelet therapy was not considered sooner to be compared in a rigorous randomized, control trial for DVT prevention. However, experimental data directly supporting the role of the platelet in DVT were generally lacking. One early report with an experimental rodent model suggests platelets directly contributed to acute venous thrombosis,16 but most experimental venous thrombosis research over the last 2 decades has focused on the role of the leukocyte and vein wall.17,18 This is because of the classic dogma that the fibrin rich red clot formation in venous thrombosis is primarily driven by the clotting pathway, whereas arterial thrombosis is thought to be more platelet driven. However, recent experimental data using murine models suggest that the platelet is a critical component of early DVT. First, the assembling and colocalization of the coagulation cascade occurs on the platelet surface in juxtaposition to the endothelium.19 Second, release of von Willebrand Factor provides a bridge between the platelet and endothelium. Studies using von Willebrand Factor gene–deleted mice confirmed decreased thrombus size that was not reversed with exogenous factor VIII, in a flow-limited venous thrombosis model.20 Extrapolation of data to humans is somewhat limited with any animal model system of human disease, including partial or total stasis DVT models.21 Particularly relevant to the current INSPIRE study is that there are no animal models (yet) of recurrent DVT.

The pathophysiology of recurrent unprovoked DVT may be different than primary DVT. How? It is likely the vein wall is damaged with the initial thrombus insult, even in those who fully lyse their DVT. Although direct tissue histopathologic examples are rare, post-DVT vein wall changes are exemplified physiologically by valve reflux and thickened and noncompliant vein walls, which together culminate in post-thrombotic syndrome. Thus, the endothelium that is regenerated after the thrombus has cleared may be more likely to thrombose. Intriguingly then, the current clinical data suggest the platelet may be more central to recurrent DVT than primary DVT.

How to take this information and make current recommendations? We suggest that for patients who have unprovoked (idiopathic) VTE and are at high risk for recurrence and would normally need long-term or life-long anticoagulation, they remain on either oral VKA or 1 of the NOACs and not undergo aspirin therapy (Figure). On the other hand, for patients with unprovoked VTE and moderate risk for recurrence, the use of 1 aspirin per day rather than nothing would be indicated. For those patients with an unprovoked VTE and low risk for recurrence, no further therapy is indicated. For patients with a provoked VTE, a total of 3 months of anticoagulation is indicated. Many questions remain and are not answered from the current data, including the following:

Figure. Incorporation of ASA into VTE extended treatment paradigm. Low risk = patients with normal D dimer and no risk factors for venous thrombosis. Moderate risk = patients with ≥1 risk factors for recurrent thrombosis. High risk = patients with inherited thrombophilias, >1 episode of venous thrombosis. ASA indicates aspirin; and VTE, venous thromboembolism.

  1. Is there an optimal length of aspirin therapy in patients with unprovoked VTE and a moderate risk for recurrence?

  2. Should aspirin be used in those patients with unprovoked VTE and low risk for recurrence?

  3. For patients with a provoked VTE who normally would not need long-term anticoagulation (a patient with a first episode of VTE and a cause which has reversed such as VTE associated with surgery or with the use of oral contraceptives), is taking 1 aspirin per day at the end of a full course of anticoagulation beneficial?

  4. Will other medications such as statins synergize with aspirin to reduce the incidence of recurrent VTE?

  5. Will the more potent antiplatelet theinopyridines be more or less effective than aspirin?

  6. Because patients with cancer represented only a small proportion of patients and patients with coronary artery disease were excluded, what are the recommendations in these groups of patients?

  7. Finally, will the current data on only a little >1200 patients hold up in day to day clinical use?

As is the case with all good studies, more questions remain to be answered and are the seeds for future studies.




The opinions expressed in this article are not necessarily those of the editors or of the American Heart Association.

Correspondence to Thomas W. Wakefield, MD, University of Michigan, CVC 5463, 1500 E. Medical Center Drive SPC 5867, Ann Arbor, MI 48109-5867. E-mail

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Aspirin a viable treatment for serious blood clots, study shows

The results suggests low-dose aspirin prevented about one third of recurrent blood clot events.

“These results suggest that aspirin prevents about one third of recurrent blood clot events. For every 1000 patients treated for one year, aspirin can be expected to prevent about 20 to 30 episodes of recurrent major thrombotic events at the cost of about three significant bleeding episodes.”

Operating since 2003, the ASPIRE study completed recruitment of 822 participants from five countries including Australia, New Zealand, Singapore, India and Argentina. All the participants had previously suffered a DVT or PE that occurred for no particular reason, called ‘unprovoked VTE’ (venous thromboembolism).

They had completed on average six months of anti-coagulant treatment, generally with warfarin. They were randomly allocated to receive either low dose enteric coated aspirin or a matching placebo. On average participants were followed for three years.

Dr Tim Brighton, from Prince of Wales Hospital and principal investigator of the study, explained:

“Many patients discontinue warfarin therapy after six or twelve months of treatment due to the inconvenience of regular blood tests and the increased risks of serious bleeding .”

“Aspirin reduces the risk of important blood clotting event including recurrent VTE, myocardial infarction, stroke, or cardiovascular death. We now have clear evidence that aspirin is of benefit for patients who are unable or do not wish to continue warfarin in the long term.”

The study results are consistent with the findings of an Italian study, called WARFASA, which a showed a significant benefit with aspirin as reported in The New England Journal of Medicine earlier this year.

When combined, the results of the two trials show clear and consistent evidence that aspirin prevents recurrent blood clots and this is likely to be adopted into future international practice.

Aspirin may be a promising treatment for those who can’t take anti-clotting drugs long term to prevent blood clots in the veins, according to new research.

Known as venous thromboembolism, the clots are typically in the deep veins of the legs and can break off, travel to the lungs and block lung arteries, a condition known as pulmonary embolism, which can be fatal.

Researchers found that aspirin reduced the risk of recurring blood clots by up to 42 percent.

In a combined analysis of two different studies, 1,224 patients received 100 mg of aspirin a day to treat blood clots and researchers monitored them for at least two years.

Although the study yielded clear results, researchers advise patients to talk to their doctor about taking aspirin after stopping treatment with anticoagulants.

“It is not recommended that aspirin be given instead of anticoagulant therapy, but rather be given to patients who are stopping anticoagulant therapy or for whom such treatments are considered unsuitable,” said John Simes, M.D., lead author of study and director of the National Health and Medical Research Council Clinical Trials Centre and professor at the University of Sydney in Australia.

According to researchers, without treatment, people who have blood clots in their veins with no obvious cause have on average a 10 percent risk of another clot within the first year and a 5 percent risk per year thereafter.

“The treatment is warfarin or a newer anticoagulant usually given for at least six to 12 months to prevent a further blood clot,” Simes said. “However, these people continue to be at risk.”

Co-author Cecilia Becattini, M.D., explained the benefits of aspirin. “Aspirin does not require laboratory monitoring, and is associated with about a 10-fold lower incidence of bleeding compared with oral anticoagulants. We are convinced that it will be an alternative for extended prevention of venous thromboembolism after 6 – 12 months of anticoagulant treatment.”

More than 250,000 people in the United States are hospitalized annually with deep vein thrombosis, the third most common cardiovascular illness.

The article was published in the American Heart Association’s journal Circulation.

Additional Resources:

  • Anti-Clotting Agents Explained
  • Understand Your Risk for Excessive Blood Clotting
  • DVT facts

Blog Post

Having a blood clot in a deep leg vein can be a very serious problem. While the clot may not do much damage there, it can block blood flow to surrounding tissue. The biggest threat, though, is that the clot, called a DVT, will break loose and travel to the lungs. There, it can cause a pulmonary embolism. This can create serious health issues, and can even result in death. Dissolving the clot before it breaks loose and travels, and preventing other clots from developing in the future, are both goals of deep vein thrombosis treatment.

The Dangers of a DVT Blood Clot

While not all pulmonary embolisms result in death, or even in any serious damage to the lungs, heart, or other organs, the possibility of these issues is very real. These embolisms come from blood clots in other areas of the body, which travel through the veins and end up back in the lungs. In some cases the clots even travel through the heart, and that can easily trigger a heart attack. By moving your body frequently and not sitting for prolonged periods of time, you can reduce your chances of developing a DVT. However, movement is not a guarantee and once a clot has occurred there is a higher risk of having another one.

How Aspirin Can Help with Deep Vein Thrombosis

The main treatment option for deep vein thrombosis is Warfarin or another brand of blood thinner. These medications can be very effective, but they are not without risk. Vein doctors and others who prescribe them understand that too much bleeding can occur in some patients, and there are side effects that are not always well tolerated.

If you visit a vein clinic or hospital for a blood clot and blood thinners are suggested to you, taking aspirin may be an option, instead. It is not for everyone, and will not be enough in all cases, but it does have a similar effect and may work well to reduce the chances of another blood clot in the future. Because aspirin thins the blood but not as strongly as prescription medications, it also reduces the chances of problematic bleeding for some patients.

Working With Your Doctor for Vein Health

Vascular surgeons, cardiologists, and other doctors who are treating you should be consulted before choosing aspirin instead of a prescription blood thinner. In some cases, aspirin will not provide enough protection. Additionally, it may not work to dissolve a clot properly. Instead, it may be better as a preventative measure after a clot has been thoroughly dissolved by another medication. When you work with your doctor, though, you can find out what will be right for you and choose the option that will offer you the best long-term health and protection from further blood clots.

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