Will my cold last longer if I swallow mucus?

Mucus is gross. But here are 9 things you should know about it.

Mucus is not widely considered a topic for polite conversation. It’s something to be discreetly blown into a tissue, folded up, and thrown away.

But the simple truth is that without mucus, you wouldn’t be alive.

“Mucus is essential for the protection of your body,” says Jeffrey Spiegel, an ear, nose, and throat surgeon at Boston University. “It’s a protective barrier and it allows you to breathe comfortably. If you had no mucus, you’d be quite sorry you didn’t.”

Given how important mucus is — and how often colds and allergies cause mucus-related symptoms — it’s worth learning a bit more about it.

1) You produce about 1.5 quarts of mucus a day — and swallow the vast majority

Most of us think of mucus as something that leaks from our nose, but the truth is that it also gets secreted in your trachea and other tubes that carry air through your lungs, where it’s technically called phlegm. Wherever it’s produced, mucus is a mix of water and proteins, and most of it gets pushed to the back of your throat by microscopic hairs called cilia.

Microscopic cilia flap back and forth continuously to push mucus to the back of your throat. (American Rhinologic Society)

Whether you’re aware of it or not, you’re constantly swallowing all this mucus, and it harmlessly ends up in your stomach. “You’re swallowing, on average, twice a minute — even when you’re sleeping at night,” says Michael Ellis, an ear, nose, and throat doctor at Tulane University.

Ellis says that, on average, a person produces about 1.5 quarts of mucus per day, and contrary to what you might think, it doesn’t vary by all that much. But that mucus gets diluted by a separate, watery secretion (called serous fluid), which can vary widely based on your health.

2) Mucus is basically the body’s flypaper

Even grosser than mucus. (.com)

Mucus has two main functions: it keeps the nasal cavity and the other airways inside your body moist, preventing them from drying out due to all the air that flows over them. (Relatedly, the serous fluid that mucus is mixed with also moistens the air itself before it enters the lungs.)

Mucus’ other function, though, might surprise you. “Mucus is kind of like flypaper,” Ellis says. “Debris that comes into the nose or throat sticks to it, and then you swallow it, so it doesn’t get into your lungs.”

Mucus, in other words, is nature’s filter for your delicate lungs. The bacteria, dust and other tiny particles that you breathe in get stuck in mucus and pulled down into your stomach, where they’re destroyed by enzymes.

3) There are two different things that cause runny noses


When a cold or allergies cause your nose to run, it’s because they’re triggering an inflammatory response in your nasal cavity and airways. Even though you always produce roughly the same amount of mucus, this dramatically increases the amount of the serous fluid it’s diluted in.

We tend to experience this as an excess of watery, runny mucus, and it can be treate by taking an anti-histamine, which reduces the amount of water — leading to thicker, drier mucus.

Cold weather causes a runny nose in an entirely different way. In cold temperatures, your cilia (the microscopic hairs that sweep mucus to the back of your throat) stop sweeping back and forth as quickly, causing some of the mucus to drip down through your nose instead.

4) A stuffy nose isn’t stuffed full of mucus — it’s swollen

The nose is mostly filled by conchae. (Bruce Blaus)

The inside of your nose is filled with structures called conchae, or turbinates. Their primary function is to warm the air you inhale to body temperature and add moisture until it’s very humid — so that the air can enter your lungs without causing problems.

Stuffy noses occur when the conchae rapidly swell in size in response to cold, dry conditions, so there’s more surface area for the air to flow over. Additionally, if you’re fighting an infection, the conchae can swell further with blood, in order to bring more white blood cells to the site of the infection.

“We call it congestion when get swollen up, because it seems like we’re having trouble getting air through,” Ellis says. Most people think of this congestion as a result of too much mucus — but in reality, it’s just swollen conchae.

This explains why many people are congested when they wake up in the morning (after breathing cold, dry air all night), especially because central air and heating systems dry out air significantly.

5) The best way to decongest your nose is with steam


Because cold, dry air is what most often causes your conchae to swell, the best remedy is to add hot, moist air. This is why taking a hot shower often opens up a clogged nose, and why hot washcloths and facial steamers are also effective treatments.

Nasal decongestants (such as pseudoephedrine and phenylephrine) can also help de-swell the conchae, but in some cases, there’s a downside: they dry out the nasal cavity, by reducing the amount of serous fluid. So if you’re also experiencing excessively thick, dry mucus, you’re better off avoiding decongestants.

6) Thick mucus could mean you’re dehydrated


A few different factors can reduce the production of serous fluid in your nose, leading to thick, dry mucus. This is often experienced as post-nasal drip — thick mucus at the back of your throat that’s much more noticeable than the thinner mucus you swallow unconsciously.

One cause is dehydration: if your body doesn’t have enough water, it’ll cut back on the secretion of serous fluid. An excessively dry environment — often caused by central heat or air conditioning — can also cause the same problem, as can smoking cigarettes.

Instead of taking a decongestant to relieve post-nasal drip, Ellis recommends using an expectorant, which will increase the amount of serous fluid your mucus is diluted in.

7) Boogers are just dried mucus

Everybody does it. (.com)

Most of the mucus in your nose gets swept by your cilia to the back of your throat. But sometimes — especially in arid environments — some of the mucus near your nostrils (in an area formally called the nasal vestibule) begins to dry out first, becoming too viscous to be swept by cilia. If it sits there long enough, it dries even further, becoming the crusty accretion colloquially known as a booger.

Boogers, as it happens, are the subject of some scientific study. Several researchers have considered the question of why people pick their noses. One theory is that people simply derive pleasure from the act of “cleaning up,” and while tissues aren’t always available, your fingers are.

Whatever the reason, it’s widespread. The authors of one small survey finding that 91 percent of adults admitted to picking from time to time. But that doesn’t mean it’s a good idea: Dutch researchers, among others, have found that nose-picking can spread infections.

8) The color of your mucus can tell you a lot

Mucus, in its natural state, is clear. But that doesn’t mean that colored mucus is necessarily a bad thing.

Grey, whitish, or yellowish mucus could simply be the result of dust, pollen, or other particles you’ve inhaled from the air around you. On the other hand, these colors can be a sign of an infection, as they can be caused by an excess of white blood cells or pus. And darker colors — like pink, red, or brown — can be a sign of bleeding in your nasal cavity.

9) Afrin is powerfully addictive

Don’t use this. (Coronades03)

The nasal decongestant spray Afrin (which has the active ingredient Oxymetazoline) works really, really well. Too well.

Afrin relieves congestion by cutting down on blood flow to the conchae, rapidly reducing swelling and opening up the nasal cavity. But soon after it wears off, it leads to rebound swelling, with the conchae getting even bigger than they were before. As a result, many people become totally dependent on Afrin, continuing to use it to fix congestion that it’s causing in the first place.

“Once you start spraying, you can’t stop,” Ellis says. “If you go more than three or four days, the nose becomes so dependent on that it’s almost like heroin.” Afrin bottles do have a fine print warning telling people not to use the medicine for more than three days, but so many people miss it that there are Afrin addiction support groups online. Ellis, among others, thinks the spray should be a prescription-only medicine.

Is it unhealthy to swallow your own phlegm?

Apart from driving your co-workers mad from the sniffling and carrying around a box of tissues like it’s a fashion accessory, what comes with colds and flus is of course, phlegm.

Yep, when you have a respiratory illness, you might see a range of different colours of mucus or snot when you blow your nose – but have you ever thought whether it’s better to er, spit or swallow?

Well users of question and answer site Quora have. They posed the question ‘Is it unhealthy to swallow one’s own phlegm during a cold or a flu? Are there any ill effects or benefits from swallowing or not swallowing phlegm?’

First up, an explanation of the fluid for you. According to the University of Kentucky College of Medicine’s Dr Brett Comer, phlegm is mostly just a mix of water, salt and a few antibodies. As Comer tells Men’s Health, it’s an ordinary part of your body, but it really goes into production overdrive during colds – your body’s lockdown response to get rid of anything that could make you sick.

So with that explained, you’d want to get rid of it, right? Actually, no, phlegm is fine to swallow and here’s why.

“The germs that find the nose and sinuses happy places to live like warm, moist, oxygenated areas- like the nasal sinuses, don’t routinely enjoy the high acid, hypoxic environment in the stomach. So I’d say that although it’s good to get it out, swallowing it is low risk,” writes nurse Bethann Siviter.

Doctor and pediatrician Ashok Banga, agrees explaining, “Mucus is their own secretion. The bacteria and viruses, whenever trapped in mucus are mostly killed in acidic environment of stomach or passed out of gut through foecal matter.”

In other words, your gut has you covered for killing the bacteria – where the risk comes is if your phlegm is mixing with someone else.

“Phlegm in a person with a respiratory infection can contain bacteria (or viruses). As any ICU nurse knows, this is one reason why people wear masks around others with serious respiratory infections,” writes neurosurgeon Dr Laszlo Tamas. “Swallowing phlegm probably reduces the chance of spreading infection to those around you. And as a practical matter, it is certainly safe to swallow phelgm if the cause is asthma, or a relatively innocuous lung infection.”

So there you have it – despite what your parents told you, phlegm won’t give you a tummy ache, or prolong your cold. Consider it permission to swallow your mucus when nobody’s looking.

Is it a cold or the flu?

Is it a cold or the flu?

Why Oh Why Is There Phlegm?

Phlegm can give clues to what’s going on inside. But as with so many things phlegmy, mysteries remain. Alex Reynolds / NPR hide caption

toggle caption Alex Reynolds / NPR

Phlegm can give clues to what’s going on inside. But as with so many things phlegmy, mysteries remain.

Alex Reynolds / NPR

Struggling through a nasty round of bronchitis with little better to do than binge watch Netflix and feel epically sorry for myself, I pondered the ageless cold-and-flu-season question: Phlegm. Why?

It begs an answer. The human body is capable of such constant wonder, so much to awe and inspire. And then, phlegm. And not just a little phlegm. Gobs. It’s the only word that really describes the whole phlegm experience.

So I started asking around, and in so doing have learned that there’s a lot more to phlegm than meets the Kleenex.

First, some definitions. Phlegm is really just one form of mucus, which the body produces all over the place to perform useful tasks, says Murray Ramanathan Jr., medical director of otolaryngology head and neck surgery at Johns Hopkins Medicine in Bethesda, Md. And because he suffers from chronic sinusitis himself, he gets the whole mucus thing on a pretty personal level.

“The entire lining of the respiratory tract, which includes the nose all the way to the bottom of the lung, makes mucus,” he says. Phlegm, he says, is limited to mucus made in the lung and in the trachea.

Or as Mark Rosen, a pulmonologist at Mount Sinai in New York and a past president of the American College of Chest Physicians, puts it: “Phlegm is something you cough up, not something you blow out.”

When everything is running smoothly, we produce phlegm and mucus every day — about a liter, Ramanathan says. We usually swallow that daily production without even noticing.

Both mucus and phlegm act as general maintenance and cleaning mechanisms, keeping airways moist and tidy and defending against the host of pollutants, particles, viruses and other things that do not belong in your nose or lungs.

“That’s often what you see when you blow your nose,” says Ramanathan, who studies the role of pollutants and environment in respiratory issues. “In foreign countries where diesel exhaust is a major contributor to air pollution and some people use wood fires indoors for cooking, you actually see black deposition and particles from the air pollution.”

But mucus also has an immunological role in sniffing out trouble. It provides proteins that are antiviral and antibacterial. Receptors on the epithelial cells in the airway sense threats and create bug-fighting enzymes in the mucus, which moves along via the cilia—microscopic hair-like structures that can provide propulsion to help eject the foreign substance.

What we call smoker’s cough, Ramanathan says, “is when the components of cigarette smoke get into the lung and cause mucus to be produced, because cigarette smoke is an irritant to the respiratory lining in both the nose and the lung.”

This primary defense system can be overwhelmed by viruses, bacteria and the resulting inflammation of the airway. That’s when mucus and phlegm production go into overdrive. And often with the increase in quantity, the quality changes too, becoming thicker to better trap and remove the offending material. Before you know it, you’ve achieved gobs status.

Sometimes phlegm can morph from its usual clear to yellow or green, a byproduct of the white blood cells that have charged in to fight infection. And then we as patients get asked that question — What color is it? — since color can sometimes, although not always, indicate the presence of infection.

As someone who tries to avoid inspection of my own snot or phlegm, I’ve always found this a rather disgusting query. But Ramanathan sees it another way. “As a sinus doctor, one of the worst nightmares you get is when people bring into the office the little Ziploc baggie of, ‘Look what I coughed out yesterday!’ In rare cases, they bring in Tupperware.”

So what to do to survive the phlegm stage, besides stock up on tissues and make sure the iPad is fully charged for the Netflix binge? Antibiotics will only help if you have a bacterial infection, and the average cold, no matter how phlegmy, usually doesn’t qualify.

“Just because your phlegm is green doesn’t mean you need antibiotics,” Rosen says. “Your cold and mine, even if you’re coughing up stuff, is usually viral, and there are no antibiotics for a virus.”

If your phlegm gets too gob-like (technical term), over-the-counter meds like Mucinex can help thin it, which makes it easier to expel, Ramanathan says. For the sinuses, using a Neti pot or decongestants can aid the mucus flow, and bending over a pot of steaming water helps some people with the symptoms, he says. I can revert straight to my childhood with the scent of Vicks VapoRub, doubling the comfort factor. And of course, chicken soup.

Eventually, as the illness subsides and the airway calms down and is no longer irritated (phlegmatic, you could say), the system goes back to producing our regular ration of mucus. Something for which we should be grateful every day.

Poet and journalist Wendy Mitman Clarke last wrote for Shots about giving children a bedtime pass. She has contributed to Smithsonian and other magazines.

Depending on the symptoms and cause of the bronchitis, treatment options include:

  • Antibiotics may be ordered to treat acute bronchitis that appears to be caused by a bacterial infection or for people who have other lung diseases that put them at a greater risk of lung infections
  • Bronchodilators, which open up the bronchi, may be used on a short-term basis to open airways and reduce wheezing
  • Cool-mist humidifiers or steam vaporizers can be helpful for wheezing or shortness of breath. Leaning over a bathroom sink full of hot water with a towel loosely draped over the head can also be help open the airways.
  • Corticosteroids given in an inhaler are sometimes prescribed to help the cough go away, reduce inflammation and make the airways less reactive. They are most often given when the cough remains after the infection is no longer present.
  • Cough medicines should be used carefully. While they can be helpful to suppress a dry, bothersome cough, they should not be used to suppress a cough that produces a lot of sputum. When the cough is wet, expectorants can help thin the secretions and make them easier to cough up. When a lot of mucus is present, coughing is important to clear the lungs of fluid.
  • For viral bronchitis, antibiotics will not be effective. If influenza causes the bronchitis, treatment with antiviral drugs may be helpful.
  • Over-the-counter pain relievers, such as aspirin, acetaminophen or ibuprofen, can be used for pain relief and fever reduction. Children with bronchitis should not be given aspirin; instead they should take acetaminophen or ibuprofen.
  • Plenty of fluids – enough to keep the urine pale (except for the first urination of the day, when it is usually darker)
  • Rest, especially if a fever is present

We tend to notice mucus only when it’s abnormal and the sticky fluid is expelled from orifices. But actually it’s pretty amazing stuff. Every moment of our lives mucus is protecting our internal organs, including the sexual organs and bowels. Here, though, we’ll focus on the airways.

What is mucus?

Mucus is 95% water, 3% proteins (including mucin and antibodies), 1% salt and other substances. Mucin droplets absorb water and swell several hundred times in volume within three seconds of release from mucus glands. Mucus strands form cross links, producing a sticky, elastic gel.

The solid gel layer acts as a physical barrier to most pathogens and the constant flushing movement prevents the establishment of bacterial biofilms. However, the pore size of the gel mesh means small viruses can easily penetrate it.

Anatomy of the airways

Both nasal cavities combined have a surface area of 150 square centimetres, aided by bony folds on their side walls. The turbulent airstream means 80% of particles are filtered here, so the adhesive properties of mucus are vital.

The blood flow to the nose varies with changing outside temperature, acting like a reverse-cycle air conditioner for the lungs.

Mucus is constantly produced (although in lesser quantities during sleep) and moved along. The mucus carries with it dead cells and other dust and debris, ending up in the stomach for recycling.

Many cells lining the airways have a long, tail-like hair, called cilia. Cilia beat at ten to 12 times per second, propelling mucus at one millimetre per minute.

Lung airways also have cilia, working hard to move mucus uphill against gravity. Mucus from the lungs is sometimes termed “phlegm”, and then “sputum” once it has been spat out.

The nose produces over 100 millilitres of mucus a day and the lungs produce approximately 50 millilitres daily.

Mucus and airways disease

Mucus assists in fighting infection when white blood cells and antibodies are excreted into the mucus film. The amount of mucus and watery liquid is increased to flush away infection, irritants or allergens.

Viruses that damage respiratory lining cells also damage cilia, so a runnier mucus layer is more easily propelled. When the cilia just can’t keep up, the body deploys other strategies such as coughing, blowing the nose, sneezing and every parent’s favourite, the snotty nose.

Chronic lung disease such as chronic bronchitis and cystic fibrosis cause mucus glands to multiply three to four times above normal levels, resulting in more viscous mucus that the cilia can’t easily clear.

Your airways use mucus to catch particles and cellular debris and move it uphill for excretion. Hey Paul Studios/Flickr, CC BY

Dehydration and some medications such as nasal decongestants reduce the effectiveness of cilia by lowering the ciliary beat frequency.

Even a frequent and repetitive cough can fatigue the cilia, leading to slower transit and increased stickiness of the mucus. That’s why many people have a prolonged “post-nasal drip” cough after colds and hay fever, as the mucus that has dripped down from the back of the nasal cavity isn’t cleared.

Saline (salt solutions) increase ciliary beat frequency and have demonstrated benefit in respiratory disease, from sinusitis to cystic fibrosis.

A ‘chesty cough’?

There is a common belief that a moist (chesty) cough indicates a chest infection. But in young, healthy people, post-nasal drip of mucus is more common than bronchitis or a chest infection.

It is extremely difficult to judge whether the sputum in the throat arose in the lungs or dripped down from the back of the nasal cavity. And mucus vibrating near the vocal cords sounds chesty no matter where it came from.

But the timing of cough may be helpful for diagnosis: a post-nasal drip cough is worse when lying down and for a while after rising from bed in the morning.

Green phlegm

Another misconception is that green mucus indicates bacterial infection and thus requires antibiotic treatment.

A number of research studies have shown poor correlation between mucus colour and significant infection. The yellow and green colours actually come from white blood cells (leucocytes) that fight infection, but are also more prominent the longer the mucus has “stuck around for”. So morning sputum may be more coloured than later in the day.

The diagnosis of a bacterial infection is made when a combination of symptoms and findings exists, with mucus colour not being the most important of these.

Unfortunately this misconception extends to some GPs. Patients with green sputum are prescribed antibiotics three times more often than patients coughing clear sputum. However, for patients with a bad cough, this prescription did not improve their recovery.

Snotty noses are a flood of mucus to wash away the viral ‘cold’. But it’s no excuse not to use a tissue. Joshua Wachs/Flickr, CC BY-NC-ND

Mucus can be colourful stuff, extending from clear to yellowy-green, but also orange, brown and grey.

Orange and brown comes from the presence of blood in mucus, of variable concentrations and ages. This blood commonly comes from the nose, due to inflammation, infection or side effects of nasal medication, without an obvious nose bleed.

Blood-stained sputum from the lungs may indicate a more serious illness.

Milk and mucus

Many people believe milk and dairy products stimulate the production of extra mucus, so should be avoided in those with hay fever and asthma. This perception arises from the short-term change in consistency of mucus and saliva in the mouth and throat.

But research evidence shows no difference in measured mucus output. Another “blinded” study compared identical-looking dairy and soy products and found no difference in amount or perception of mucus.

To spit or swallow?

I’m occasionally asked whether swallowing mucus produced with a respiratory infection is harmful. It’s not; luckily the stomach works to neutralise bacteria and recycle the other cellular debris.

Some people do report a queasy feeling in the stomach during such infections. This is more likely due to air swallowed from repeated throat clearing and the infection itself, rather than increased mucus getting to the stomach.

Freelance journalist and translator Claire Dupré assisted with the drafting of this article.

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Sinus: Pain, Pressure, Drainage

Help, my sinuses are killing me! Have you ever said that? Have you ever felt like that? Have you ever taken medicine for sinuses? If you haven’t, you are unusual because every year over one and a half billion dollars worth of “sinus” medicine is purchased in America for the symptoms of sinus disease (i.e., stuffy nose, congestion, headache, and nasal drainage).

Does everyone have sinuses?

Yes — even a newborn baby has little tiny ones. Sinuses begin as pea-sized pouches extending outward from the inside of the nose into the bones of the face and skull. They expand and grow through childhood into young adulthood. They are air pockets: Cavities that are lined with the same kind of membranes that line the nose, and they are connected to the inside of the nose through small openings about the size of a pencil lead.

What do sinuses do?

Sinuses are part of the nasal air and membrane system that produces mucus. Normally, the nose and sinuses produce between a pint and a quart of mucus and secretions per day. This mucus passes into and through the nose, sweeping and washing the membranes, picking up dust particles, bacteria, and other air pollutants along the way. The mucus then flows backward into the throat where it is swallowed, down into the stomach where acids destroy any dangerous bacteria. Most people do not notice this mucus flow because it is just a normal bodily function.

What is “Post-Nasal Drip”?

When the nasal passages are irritated by allergies, air pollution, smoke, or viral infections (such as a “cold”), then the nose and sinus membranes secrete more than the normal amount of mucus. This will be a clear, watery, and profuse mucus that is supposed to wash away the irritation or allergy. This is the most common type of “post-nasal drip.” Another form of “post-nasal drip” is mucus that is thick and sticky. This occurs when the air is too dry and the nose membranes cannot produce enough moisture to put into the mucus for it to flow easily. Bacterial infections also produce a thick, sticky mucus with pus in it, turning it a yellow or green color.

What is sinusitis?

“-itis” is a medical term for infection or inflammation, so “sinusitis” is an infection or inflammation of the sinuses. A typical case of acute sinusitis begins with a cold or “flu” or an allergy attack that causes swelling of the nasal membranes and increased watery mucous production. The membranes can become so swollen that the tiny openings from the sinuses become blocked. When mucus and air cannot flow easily between the nose and sinuses, abnormal pressures occur in the sinuses, and mucus can build up in them. This creates a pressure-pain in the forehead or face, between and behind the eyes, or in the cheeks and upper teeth, depending on which sinuses are involved.

A blocked sinus cavity filled with mucus becomes a fine place for bacteria to grow. When a person’s “cold” lasts more than the typical week or so, and when his mucus turns yellow-green or develops a bad odor or taste, then a bacterial infection has probably taken over. The pressure and pain in the face and forehead can be quite severe in acute bacterial sinusitis.

Chronic sinusitis occurs when the sinus opening is blocked for an extended period. Headaches are less prominent in chronic sinusitis, but congestion and unpleasant nasal secretions usually persist. Also, fleshy growths known as polyps can develop as an exaggerated form of inflammatory swelling of the membranes.

Some cases of sinusitis come from infections in the upper teeth that extend into the sinuses.

Is sinusitis dangerous?

Most cases of sinusitis respond promptly to medical treatment and are not serious. However, an infection that is in the sinus is also very close to the eye and to the brain. Extension of a sinus infection to the eye or brain is rare. Furthermore, it is not healthy for the lungs to have infected mucus dripping down from infected sinuses. Bronchitis, chronic cough, and asthma are often aggravated, or even brought on, by sinusitis.

What is a sinus headache?

A headache in the face, cheeks, forehead, or around the eyes that comes on during a “cold,” or when the nose is congested and runny or filled with mucus, is probably a “sinus headache”: one caused by sinus infection. Another kind of sinus headache is the one that occurs in the sinus areas during descent (landing) in an airplane, especially if you have a cold or active allergy (this is called a vacuum headache).

Unfortunately there are many other causes of headaches that can be confused with sinusitis. For example, migraine and other forms of vascular or “tension” headaches also give pain in the forehead and around the eyes, and they may even cause a slight stuffy-runny nose. But they are more likely to come and go away in a day or so without a physician’s treatment, whereas sinusitis usually gives a headache that lasts for days or weeks until it is treated with antibiotics. Furthermore, intermittent headaches that cause nausea and vomiting are more typical of a migraine-type headache than sinusitis. Severe, frequent, or prolonged headaches deserve a visit to a physician for diagnosis and treatment.

Who gets into sinus trouble?

Actually, anyone can “catch” a sinus infection, but certain groups of people are more likely to develop sinusitis:

  1. People with allergies: An allergy attack, like a “cold,” causes swelling in the nasal membranes that will block the sinus openings, obstruct the mucous drainage, and predispose to infection.
  2. People with deformities of the nose that impair good breathing and proper drainage: examples are a crooked nose or a deviated septum (the structure between the nostrils that divides the inside of the nose into right and left sides).
  3. People who are frequently exposed to infection: school teachers and health workers are especially susceptible.
  4. People who smoke: Tobacco smoke, nicotine, and other pollutants impair the natural resistance to infection.

What will a doctor do for my sinuses?

Your physician will ask you questions about your breathing, the nature of your nasal mucus, and the circumstances (time of day or seasons) that give you symptoms. Be prepared to explain your headaches: When and how often they occur, how long they last, and if they are associated with nausea, vomiting, vision changes, or nasal congestion. An otolaryngologist-head and neck surgeon is the kind of physician who will especially examine your ears, nose, mouth, teeth, and throat with particular attention to the appearance of your nasal membranes and secretions. He/she will check for deformities of your nose that impair breathing and for tenderness over your sinuses. X-rays of your sinuses might be needed.

Treatment will depend on the diagnosis that your physician establishes, Infections may require either antibiotics or surgery or sometimes both. Acute sinusitis most likely will improve on medication, but chronic sinusitis more often requires surgery. If your symptoms are due to allergy, migraine, or some other disease that mimics sinusitis, your doctor will have alternative treatment plans.

What can I do for my own sinuses?

  • Manage your allergies if you have them (write for the Academy’s pamphlet Hayfever, Summer CoIds and Allergies). Use a humidifier when you have a cold, and sleep with the head of your bed elevated. This promotes sinus drainage. Decongestants can also be helpful, but they contain chemicals that act like adrenaline and are dangerous for persons with high blood pressure, irregular heart rhythms, heart disease, or glaucoma. They are also like stimulants that can produce sleeplessness. Send for the Academy’s pamphlet Antihistamines, Decongestants and “Cold” remedies.) You should consult your physician before you use these medications.
  • Avoid air pollutants that irritate the nose, especially tobacco smoke.
  • Live by good health practices that include a balanced diet and regular exercise.
  • Minimize exposure to persons with known infections if possible, and practice sanitary health habits when you must be around them (such as hand washing and avoidance of shared towels, napkins, and eating utensils).

A large variety of non-prescription medications are sold as sinus remedies, but it is folly to try them before a proper diagnosis is established. The best advice you can ever get, of course, is what is given to you by your physician who evaluates your own special symptoms and examines your own nose and sinuses.

©1992. American Academy of Otolaryngology-Head and Neck Surgery, Inc. This leaflet is published as a public service. The material may be freely used so long as attribution is given to the American Academy of Otolaryngology-Head and Neck Surgery, Inc., Alexandria, VA.

See Dr. Levy’s article on Sinusitis, What is Sinusitis?.

See Dr. Reiber’s article on Sinus Headache.

What can sputum tell us?

Share on PinterestSputum is a type of mucus that may be expelled when coughing.

There are many different reasons for the body to produce excess sputum. Below is a list of some of these causes, along with how the sputum may appear.


In smokers, mucus builds up in the lungs, causing a “smoker’s cough.” The sputum produced may be green, yellow, or bloody.


People with asthma have airways that are sensitive to allergens, environmental pollution, and respiratory infections. This sensitivity can lead to the airways becoming inflamed, as well as an increase in mucus production.

Cystic fibrosis

Cystic fibrosis is an inherited disease caused by a defective gene. It leads to smaller airways becoming blocked by thick mucus, which causes breathing difficulties.

The thick mucus in cystic fibrosis becomes an ideal environment for bacteria to grow. Many people with cystic fibrosis develop chronic bacterial lung infections.

Respiratory tract infections (RTI)

Sputum that is a different color from saliva may be a sign of a lower RTI. With bacterial RTIs, sputum may also have a thick consistency and an unpleasant odor.

As a general rule, sputum is dark green in the early stages of an infection and gradually lightens as the infection improves. It is the presence of an enzyme called myeloperoxidase that gives the sputum its green color, during an infection.

Some infections may cause sputum to be yellow, gray, or rusty colored.

Common RTIs

Share on PinterestThe flu is a common type of RTI, which may cause sputum.


Flu, or influenza, may result in green phlegm. The main symptoms are:

  • high temperature, of 100.4°F or above
  • tiredness
  • weakness
  • headache

Other common symptoms include general aches and pains, a chesty cough, and cold-like symptoms, such as a blocked or runny nose, sneezing, and a sore throat.

People should rest at home, drink plenty of water, and keep warm. Over-the-counter painkillers will help when someone has the flu, and most people will start to feel better within a week.

If started within 2 days of becoming ill, antiviral drugs such as oseltamivir can lessen the time someone is sick by 1-2 days. Taking antiviral drugs later in the infection can also be beneficial, particularly if someone is very ill or has a high risk of developing complications.


Bronchitis is an infection of the lung’s main airways, the bronchi, which become inflamed and produce extra mucus. People with this condition may cough up yellow-grey or greenish sputum.

Bronchitis is a lung condition that can be acute or chronic.

Acute bronchitis lasts about 3 weeks. Chronic bronchitis is defined as a daily cough that produces sputum and lasts for at least 3 months and occurs for two consecutive years. It is a symptom of other lung conditions, including emphysema and chronic obstructive pulmonary disease (COPD).

Most cases of acute bronchitis can be treated at home with non-steroidal anti-inflammatory drugs (NSAIDs) and by drinking plenty of fluids.



Other common symptoms include:

  • difficulty breathing
  • rapid heartbeat
  • fever
  • feeling generally unwell
  • sweating and shivering
  • loss of appetite

If someone thinks that they have pneumonia, they should see a doctor.

Tuberculosis (TB)

If someone has TB, they may cough up green or bloody phlegm. They will also experience symptoms that can include:

  • weight loss
  • night sweats
  • fever
  • tiredness
  • loss of appetite
  • swelling in the neck

TB is a serious condition but can be treated with a 6-month course of antibiotics.

Although TB is a bacterial infection that mainly affects the lungs, it can impact on the upper body, glands, bones, and nervous system, as well.

The physiology of mucus and sputum production in the respiratory system

The main function of the respiratory system is to draw air into the lungs to allow the exchange of gases with blood circulating to the lungs.


VOL: 99, ISSUE: 23, PAGE NO: 63

Marion Richardson, BD, CertEd, DipN, RGN, RNT, is senior lecturer and programme leader, emergency nursing, University of Hertfordshire

This blood supplies the cells of the body with oxygen and removes the waste products of metabolism. Tissues of the respiratory tract are thin and delicate, and become thinnest at the surfaces of the aveoli, where gaseous exchange occurs. The body has a number of mechanisms which protect these tissues and ensure that debris and bacteria do not reach them.

Tiny hairs called cilia trap large pieces of debris and waft them out of the airways; the reflexes of sneezing and coughing help to expel particles from the respiratory system and the production of mucus keeps the tissues moist and helps to trap small particles of foreign matter.

Mucus production in the airways is normal. Without it, airways become dry and malfunction. But sometimes the mucus is produced in excess and changes in nature. This results in the urge to cough and expectorate this mucus as sputum. Sputum expectoration is not normal and there is always an underlying pathological cause.


Mucus is secreted from two distinct areas within the lung tissue. In the surface epithelium, which is part of the tissue lining of the airways, there are mucus-producing cells called goblet cells. The connective tissue layer beneath the mucosal epithelium contains seromucous glands which also produce mucus.

The respiratory tract produce about two litres of mucus a day from these glands (Martini, 2003), and this is composed of water, carbohydrates, proteins and lipids. The high water content helps to humidify the passing inspired air. Mucus contains glycoproteins (or mucins) as well as proteins derived from plasma, and products of cell death such as DNA.

Mucus is sticky and this helps to trap dust particles, bacteria and other inhaled debris. Mucus also contains natural antibiotics, which help to destroy bacteria – the epithelial cells secrete a substance called defensis. Mucus also contains lysozyme, which is an antibacterial enzyme.

Movement of mucus

Cilia in the nose move the mucus formed there towards the throat where it is swallowed and digested in the stomach. In cold weather, this process slows and the mucus sometimes gathers in the nose and drips or dribbles out – a winter runny nose.

Particles larger than 4mm in diameter usually become trapped in mucus in the nose and rarely get any further down the airways. The nasal mucosa has many sensory nerve endings and large particles irritate these nerves, stimulating a sneeze – a violent burst of air – which expels the particles along with mucus.

Further down the airways, cilia in the trachea and bronchi also waft the mucus towards the pharynx to be swallowed. This movement, against the force of gravity, is sometimes called the mucus escalator. Normally, this upward movement is not noticeable, except when we clear our throats. However, if larger quantities of mucus build up, the cough receptors may be stimulated and air and mucus will be forcibly expelled from the trachea.

Moving down the airway, the mucosal epithelium gets thinner and changes in nature. There are only a few cilia and no mucus-producing cells in the bronchioles, so any airborne debris is removed by macrophages in the alveoli or coughed out.

Sputum production

Irritation of the respiratory system causes both inflammation of the air passages and a notable increase in mucus secretion. A person may become conscious of swallowing the mucus or the inflammation may trigger a coughing reflex so that they expectorate these secretions as sputum.

It seems that the inflammation of the mucosa is responsible for sputum production rather than any of the other changes that occur in diseased lung tissue (Jeffrey Maestrelli et al, 2001).

Expectorated sputum contains lower respiratory tract secretions, as well as secretions from the nose, mouth and pharynx, and cellular debris and micro-organisms (Rubin, 2002). In some disease processes, the sputum changes in nature and colour.

Airway disease and sputum

Sputum production is associated with many lung disease processes and sputum may become infected, stained with blood or contain abnormal cells.

Smoking – Smoking has many effects on the airways. Inhaled smoke destroys the cilia that are important for moving mucus to the throat for swallowing. As a result, mucus accumulates in the bronchioles and irritates the sensitive tissues there, causing a cough. Coughing is vital as it is the only way smokers can remove mucus from their lungs and keep the airways clean (Rubin, 2002). This is characterised by the ‘smoker’s cough’.

Constant coughing to clear the sputum has an effect on the smooth muscle of the bronchioles which becomes hypertrophied (enlarged or overgrown). This in turn causes more mucus glands to develop.

Smoking also causes hyperplasia (excessive cell division and growth) of the mucus-producing goblet cells (Maestrelli et al, 2001). Because of the constant irritation, more mucus is produced and collects in the alveoli, which can become overburdened and collapse.

Another effect of smoking is the development of emphysema when the alveoli expand, the capillary blood supply deteriorates and gaseous exchange is reduced. Smoking makes other lung diseases worse and is a major cause of lung, and many other, cancers.

Smoking cessation improves lung health – bronchial tubes relax and the work of breathing becomes easier, and cilia begin to regrow within a few months, so mucus and debris can be cleared without the need for constant coughing. Also, the risk of cancers reduces over time.

Bronchitis – Bronchitis is an inflammation of the bronchial lining. It is commonly related to cigarette smoking but is also triggered by environmental irritants such as chemical vapours, exhaust fumes or pesticides. In response to the inflammation, excess mucus is produced. This can block the small airways and reduce respiratory efficiency, for example, in chronic airways obstruction. Over-production of mucus leads to frequent coughing, which further irritates the tissues and causes even more mucus production.

Chronic obstructive pulmonary disease – A pattern of persistent respiratory symptoms (chronic bronchitis, chronic airway obstruction and emphysema) is termed chronic obstructive pulmonary disease (COPD). Most patients with COPD show the characteristics of mucus hypersecretion in the airways in the following ways:

– The production of sputum;

– Increased mucus in the lumen of the airways;

– Hypertrophy of submucosal mucus-producing glands;

– Goblet cell hyperplasia.

The mucus hypersecretion leads to impaired gas exchange and reduced mucociliary clearance, encouraging bacterial colonisation and exacerbations of the disease (Rogers, 2001). Mucus hypersecretion may contribute to morbidity in these patients.

Asthma (acute obstructive airways disease) – Some people’s airways are sensitive to allergens such as drugs, environmental pollution or bacteria, and this causes mast cells in their tissues to burst and release histamine and prostaglandin.

In response, the mucosa of the airways becomes swollen and oedematous, and mucus production increases in an attempt to rid the body of the allergen. Smooth muscle constricts, particularly around the terminal bronchioles, and breathing becomes difficult. Mucus transport slows and fluids accumulate in the air passages.

This hypersecretion of mucus is an important cause of illness and death in patients with asthma. No specific treatments for it are available (Fahy, 2002). The number of goblet cells increases and the patient stores and secretes more mucin, which makes the sputum thick and sticky. Asthma can be fatal, and death is usually caused by blockage of the narrow airways with a plug of sputum.

Cystic fibrosis – Cystic fibrosis is a lethal disease which is inherited and affects Caucasians of north European descent. A defective gene located on chromosome 7 means a protein called a cystic fibrosis transmembrane regulator, responsible for the active transport of chloride ions within cells, does not function normally.

This protein is abundant in cells that produce watery secretions such as mucus. The abnormality means that secretory cells cannot transport salts and water efficiently, and secretions become thick. This affects the mucus glands in the respiratory tract and secretory glands in the gastro-intestinal tract.

In the respiratory tract, the hyperviscous, sticky mucus adheres to the airways and cannot be transported properly – the mucus escalator stops working and mucus plugs block the smaller airways. Breathing becomes difficult and problems with transporting mucus may lead to bacterial colonisation.

The average life expectancy of people with cystic fibrosis in the UK is 31 years (National Services Division, 2002). People with cystic fibrosis die from chronic recurrent bacterial infections of the lungs and associated heart failure.

Sputum assessment

Sputum can provide a number of clues about a patient’s health. It is difficult to assess the amount of sputum produced in a day (Law, 2000) but there are many terms to describe it – mucoid, purulent, mucopurulent, frothy, viscous or bloodstained.

Mucus colour also varies considerably from white or opaque to grey, orange, green, brown or, occasionally, black. Yellow, orange or green sputum is commonly associated with bacterial infection. The more neutrophils that are present in sputum, the greener it becomes and patients may require treatment with antibiotics.

However, people with asthma often have neutrophils in their sputum – the sputum may be coloured but is free from infection. Red sputum indicates the presence of blood and may suggest tuberculosis or cancer.


Sputum is produced when lungs are damaged or diseased and can give nurses important information about the patient and his or her illness.

Mucus and Phlegm: Barometers of Your Health

  • Allergies, Asthma, and Lung
  • Asthma

Women. Wisdom. Wellness. Dec 5, 2018

Your body constantly produces mucus and phlegm to help protect you from infection and prevent your internal tissues from dehydrating. Though they’re always at work, you typically only notice the sticky substances when you’re sick.

Mucus and phlegm are similar, yet different:

  • Mucus is a thinner secretion from your nose and sinuses.
  • Phlegm is thicker and is made by your throat and lungs.

Both work as part of your immune system. They trap particles you breathe in through your airways – including viruses and bacteria. Each day your body makes about 1.5 liters of them — even more when you’re fighting infection.

Mucus and phlegm are made of water, antibodies, enzymes, proteins and salt. They carry dead cells, dust and other debris from the nose and lungs.

When you breathe through your nose, 80 percent of particles are filtered through the mucus lining. Tiny hairs called cilia in the nose and lungs move mucus and phlegm toward the throat.

Color Not Always a Clear Indicator

The color and consistency of mucus and phlegm offer clues as to what’s happening in your body. But the color can’t be counted on to clearly indicate whether you have a bacterial or a viral infection, says Laura Tully, MD, of Premier ENT Associates.

“Patients think that because mucus is a color other than clear – like yellow or green – that means they have a sinus infection,” Dr. Tully says. “Just because your mucus starts out green or yellow, that’s very common with a typical viral cold, and doesn’t necessarily mean you have a bacterial illness.”

She adds, “Eventually a cold can morph into something like an acute sinusitis that is bacterial.”

The color and consistency of mucus and phlegm offer clues as to what’s happening in your body.

What to Know and Do When Your Mucus Changes

Here’s a rundown of what the color and consistency of mucus and phlegm may indicate:

  • Clear. Thin and clear mucus is normal and healthy.
  • White. Thicker white mucus goes along with feelings of congestion and may be a sign that an infection is starting. The white color comes from an increased number of white blood cells. If you have asthma, lots of white phlegm may be a sign of inflamed airways. Using a preventer inhaler can help. Drink more water to stay hydrated and try saline sprays to ease a stuffy nose.
  • Light yellow or green. Mucus or phlegm of this color means your body is fighting an infection. The color comes from the enzymes in white blood cells. Get plenty of rest and stay hydrated. If you have asthma, you may be experiencing more symptoms. Be sure to use your preventer inhaler to keep your airways open.
  • Dark yellow or green. These colors – especially if accompanied by a fever, cough and sneezing – are a sign an infection is getting worse. Make an appointment with your doctor, especially if you have asthma and your inhaler is not effective.
  • Pink or red. Phlegm and mucus with a red tinge include blood. Irritation and dryness from nasal tissue can cause this. If phlegm from the lungs is pink or red, see your doctor right away. People with asthma who have a cough may bring up phlegm streaked with blood.
  • Brown. Dried blood, dirt particles and residue from smoking or tobacco use can make mucus brown. Smoking can trigger asthma symptoms and prevent an inhaler from working.
  • Black. Heavy smoking and air pollution can cause black mucus. Rarely, it can be a sign of a fungal infection. See your doctor.

What to Do with Phlegm and Mucus?

When your body is overrun with phlegm and mucus, you can blow it out, spit it out or swallow it. Any method is fine. The stomach neutralizes bacteria carried by mucus and phlegm and does its part to remove other waste lodged in the sticky substances from the body.

If you have asthma and you feel that your body is making too much phlegm, talk with your doctor about exercises and medicines that can help.

Source: Laura Tully, MD, Premier ENT Associates; Texas A&M Health and Science Center; Asthma UK; The Conversation

Laura Tully, MD

Premier ENT Associates

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