- Asthma and COPD: How to Tell the Difference
- Knowing the differences between COPD and asthma is vital to good practice
- Potential and scope
- Key points
- Different pathophysiology
- Different presentations
- Lung function measurements
- Opposite prescribing approaches
- Other strategies
- WHY IS THERE OVERLAP? WHY DOES IT OCCUR?
- Expert Answers: What Is The Difference Between Asthma and COPD?
- Is Asthma considered part of COPD?
- Chronic Obstructive Pulmonary Disease (COPD)
Asthma and COPD: How to Tell the Difference
Asthma is a long-term medical condition but is one that can be managed with proper treatment. One major part of treatment includes recognizing your asthma triggers and taking precautions to avoid them. It’s also important to pay attention to your breathing to make sure your daily asthma medications are working effectively. Common treatments for asthma include:
- quick-relief medications (bronchodilators) such as short-acting beta agonists, ipratropium (Atrovent), and oral and intravenous corticosteroids
- allergy medications such as allergy shots (immunotherapy) and omalizumab (Xolair)
- long-term asthma control medications such as inhaled corticosteroids, leukotriene modifiers, long-acting beta agonists, combination inhalers and theophylline
- bronchial thermoplasty
Bronchial thermoplasty involves heating the inside of the lungs and airways with an electrode. It shrinks the smooth muscle inside the airways. This reduces the airway’s ability to tighten, making it easier to breath and possibly reducing asthma attacks.
Asthma medications “
Like asthma, COPD is a long-term health condition, and the goal of treatment is to control symptoms so you can lead an active and healthy life. Because it is a progressive condition, another main objective of treatment is to prevent the condition from worsening. You should quit smoking and avoid exposure to secondhand smoke. This is the only way to prevent COPD from getting worse. Some quitting methods include nicotine replacement products and medications, as well as therapy, hypnosis, and support groups.
Other common treatments for COPD include:
- medications such as bronchodilators, inhaled steroids, combination inhalers, oral steroids, phosphodiesterase-4 inhibitors, theophylline, and antibiotics
- lung therapies, including oxygen therapy and pulmonary rehabilitation programs involving education, exercise training, nutritional advice, and counseling to increase your quality of life
- surgeries such as lung volume reduction surgery (removing areas of damaged lung tissue to increase space in the chest cavity for the remaining healthy lung tissue), lung transplant (replacing diseased and damaged lungs with healthy, donated lungs), or bullectomy (removal of abnormally large air spaces from the lungs to help improve breathing)
COPD: Treatment options “
Response to treatment
Both COPD and asthma respond well to treatments like quitting smoking and airway-opening medications like bronchodilators. However, lung function is only fully reversible in people with asthma. A diagnosis of asthma along with COPD often means a faster decline in lung function as COPD progresses. This is still the case even in people with mild forms of the disease.
Knowing the differences between COPD and asthma is vital to good practice
The “Outcomes strategy for people with chronic obstructive pulmonary disease and asthma” was launched in July 2011 by the Department of Health, with the overall aim to drive improvements in outcomes for patients.1 Once implemented, it is expected to help people to avoid lung disease and lead longer and healthier lives. The strategy recognises the role of community pharmacy in supporting the management of people with respiratory disease through medicines use reviews and new pharmacy services.
In addition, the introduction of national target groups for MURs in England, under amendments to the NHS Community Pharmacy Contractual Framework, aims to ensure the service is provided to those who will benefit most. One of the target groups is patients with asthma or COPD.2 Both diseases have a major impact in the UK in terms of mortality and morbidity3 and the aim of MURs with these patients is to support them to take their medicines as intended, increase their engagement with their condition and medicines, and promote healthy lifestyles, in particular stopping smoking.
Potential and scope
Asthma and COPD are the commonest respiratory diseases seen in the UK.1 In England, figures for asthma range between three million and 5.4 million and it is estimated that around 835,000 people are registered with the NHS as having COPD (ie, mostly severe disease — many are undiagnosed).1 It is reported that on average every community pharmacy has over 500 patients with either a diagnosis of asthma or COPD.4
There are both similarities and differences between asthma and COPD. It is not always easy to differentiate between them (see later), but the wrong diagnosis and inappropriate treatment will result in patients not getting the care they need. Understanding the key differences and similarities is critical for reviewing related medicines, giving correct advice and having an effective discussion.
Both conditions are characterised by various degrees of airflow limitation, mucus and inflammation, and patients often have symptoms of coughing and wheezing. However, they differ in their pathophysiology, clinical presentation, lung function measurements and drug management.
- First-line maintenance therapy in asthma is inhaled corticosteroids. In COPD, bronchodilators are first-line.
- In asthma, compliance problems include perceived lack of efficacy and the intermittent nature of the condition. In COPD compliance problems may be more about physical disability.
- A distinction between the two diseases can be difficult in practice but asking patients for their diagnosis and being clear on the differences will help improve outcomes
Although asthma and COPD are both chronic inflammatory lung disorders, perhaps the most important difference between them is the nature of the inflammation that occurs. In asthma, inflammation is mainly caused by eosinophils, whereas in COPD neutrophils are involved.5 This is an important distinction because the nature of the inflammation affects the response to pharmacological agents: corticosteroids are effective against eosinophilic inflammation but largely ineffective against neutrophilic inflammation.
It is significant, however, to note that in exacerbations of COPD and asthma the patterns of inflammation become similar. In exacerbations of asthma triggered by viruses there can be increases in the number of neutrophils in addition to the proliferation of eosinophils. And in COPD exacerbations there may be an increase in eosinophil numbers.5 This helps to explain the prescribing of corticosteroids to COPD patients in order to manage an acute exacerbation or frequent exacerbations.6
In asthma, airway obstruction results from constriction of bronchial smooth muscle, airway hyper-reactivity to allergens, and inflammation accompanied by increased eosinophils and activated T-cells. In COPD, airway smooth muscle is not usually constricted and obstruction is associated mainly with mucus hypersecretion and mucosal infiltration by inflammatory cells, leading to cellular damage and the loss of alveolar structure. Furthermore, the cellular destruction and structural changes associated with COPD interfere with oxygenation and pulmonary circulation.
The classic initial clinical presentation of asthma is a young patient with recurrent, intermittent episodes of wheezing and coughing that may be accompanied by chest tightening or shortness of breath. Wheezing on breathing out is the classic symptom, but some patients present mainly with cough, especially at night.
Asthma is most often associated with onset during childhood and is common in those with a family history of atopy or asthma. Symptoms typically increase with exposure to allergens and triggers, such as pollen, dust mites and animal dander. In some cases, asthma symptoms disappear after childhood.7
In contrast, COPD is almost unknown in children and rare in adults under the age of 40 years.7 The classic presentation is an older current or ex-smoker with progressively worsening shortness of breath and possible cough and mucus production accompanied with decreasing physical activity (often assumed to be a sign of ageing). COPD is almost always associated with a long history of smoking, while asthma occurs in non-smokers as well as smokers.
Daily symptoms are present in only 27 per cent of people with asthma, whereas in COPD symptoms are more likely to be constant.8
Lung function measurements
Asthma and COPD are both suspected if a person reports characteristic symptoms. Diagnosis requires lung function tests.
Although both diseases are obstructive, in the classic patient with asthma, airway obstruction is reversible either spontaneously or with treatment, whereas in COPD obstruction is largely irreversible.
Asthma patients can often have symptoms when they have near-normal lung function. Most patients with COPD do not become symptomatic or aware of impairment until the FEV1 (forced expiratory volume in one second) has fallen to about 50 per cent of the predicted value.
Patients with asthma do not normally experience lung function deterioration if they continue to use their inhaled corticosteroids, whereas patients with COPD continue to lose lung function despite medication.
Opposite prescribing approaches
The first-line maintenance therapy for most patients with asthma is an inhaled corticosteroid; to prevent symptoms by minimising inflammation. Therapy should be titrated up or down, based on assessment of control. Short-acting bronchodilators, such as salbutamol, are required to treat symptoms as required and patients with good asthma control should rarely need to use their short-acting bronchodilator. For patients whose asthma is not well controlled on inhaled steroid therapy alone, adding a long-acting beta2-agonist may be considered.
For COPD, the approach is opposite. Bronchodilators are the first-line maintenance treatment for COPD and are fundamental in managing the disease symptoms. Inhaled cortisteroids are not the first-line therapy and are reserved for use in combination with a long-acting beta2-agonist in patients with severe to very severe COPD and who have frequent exacerbations.
Furthermore, in COPD therapy, inhaled cortisteroids therapy is not titrated on the basis of control but rather on exacerbation rates — it may be discontinued if there is no reduction in exacerbation rates. It is important, therefore, for pharmacists to establish what patients have been diagnosed with.
The non-drug component of management of asthma or COPD is where similarities lie. They involve lifestyle modifications, such as smoking cessation, diet (ie, good nutrition and weight loss or gain depending on circumstances) and exercise.
Treatment of co-existing conditions is crucial with both disorders, to differentiate symptoms and to ensure that appropriate treatment is being provided.
Patient education also plays a key role in optimising compliance and adherence with lifestyle adjustment and pharmacological therapy.
Ensuring appropriate prescribing is an area in which pharmacists can use their expertise and skills, but they should bear in mind that, unfortunately in clinical practice, the distinction between the two diseases, especially in the elderly, can be difficult.
In addition, patients with long standing or severe asthma — especially those who have inadequately had their underlying inflammation controlled — can present with chronic irreversible airflow obstruction with reduced fixed lung function secondary to remodelling within the airway. This makes the diagnosis of asthma sometimes challenging and these patients may be mislabelled as COPD patients. Furthermore, in 10 per cent of patients with COPD obstruction can be reversed by a bronchodilator and their airways behave like those in asthma patients, responding to inhaled corticosteroids.
It should also be remembered that COPD and asthma can occur together — those with asthma who smoke are likely to develop COPD.
Although asthma and COPD have many similarities, the focus of treatment for these two diseases and the outcomes that can be expected are different. Greater clarity on these differences will contribute to improved outcomes for these patients. The Panel summarises the key similarities and differences between the two diseases.
Anna C. Murphy is consultant respiratory pharmacist at University Hospitals of Leicester NHS Trust
1. Department of Health. An outcomes strategy for chronic obstructive pulmonary disease (COPD) and asthma in England. July 2011.
4. Colin-Thome D. Long term conditions: integrating community pharmacy. Executive summary. London. The Royal Pharmaceutical Society and Webstar Health 2006.
5. Barnes P. Similarities and differences in inflammatory mechanisms of asthma and COPD. Breathe 2011;7(3):229–38.
6. National Collaborating Centre for Chronic Conditions. National clinical guideline on management of chronic obstructive pulmonary disease in adults in primary and secondary care. Thorax 2004;59(Suppl 1):1–232.
7. British Thoracic Society/Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma: a national clinical guideline. 2011.
8. Global initiative for asthma. Global strategy for asthma management and prevention. Updated 2010. www.ginasthma.org.
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WHY IS THERE OVERLAP? WHY DOES IT OCCUR?
Overlapping asthma and COPD could occur for several reasons. Asthma and COPD are two common conditions, and by chance alone there will be overlap. The two conditions may also share common risk factors or origins, which means that one may evolve into the other. One expression of this possibility, the “Dutch hypothesis”, was proposed by Orie who suggested that BHR may be a risk factor for asthma and COPD.2 Another expression of the common risk hypothesis for overlap syndrome comes from the study of childhood diseases. Epidemiological studies have identified an association between childhood respiratory illness and impaired adult lung function.27 Airway growth starts in utero and continues throughout childhood into early adult years. Any diseases or exposures that lead to incomplete airway growth may also contribute to impaired adult lung function. In this way, fetal or childhood exposures may contribute to adult asthma and COPD.28
Adult COPD may therefore result from accelerated decline in lung function, failure to attain maximal airway growth or a combination of the two (box 1). An examination of lung growth through life shows evidence for both of these circumstances (fig 6). Identification of risk factors for these events will aid understanding of COPD and suggest ways to prevent the onset of COPD. Remodelling of airway structural elements is a key factor in airway growth, and is now recognised to be an important part of the pathological processes involved in asthma and COPD.21 This suggests that there will be overlap or commonality in the risk factors for impaired lung growth and accelerated decline in airway function. Epidemiological studies have shown this to be the case. Unexpectedly, there also appears to be risk factor potentiation, where each of the more common risk factors interacts with one or more other risk factors to potentiate the development of COPD. For example, smoking and asthma are independent risk factors for COPD, and smoking itself is a risk factor for asthma. Predictably, when the risks of combined asthma and smoking are examined, then the effects accumulate, and decline in adult lung function in smokers with asthma is greater than in asthma or smokers alone.1 29
Forced expiratory volume in 1 s (FEV1) ml (corrected for height, weight and age at first survey) for males: non-smoking males without asthma (continuous line), non-smoking with asthma (dotted line), smoking without asthma (dashed and dotted line) and smoking with asthma (dashed line). (Reproduced with permission from the American Journal of Respiratory and Critical Care Medicine).
Pathways to chronic obstructive pulmonary disease (COPD)
Pathways to COPD
Accelerated decline in adult lung function
Incomplete lung growth during childhood
Common risk factors
Risk factor potentiation
Other relevant risk factors
Accelerated decline in lung function
Since COPD represents incomplete reversibility of airflow obstruction, then any risk factor that leads to accelerated loss of lung function will contribute to the development of COPD. Several risk factors for accelerated decline in include age, smoking, BHR, asthma and exacerbations or lower respiratory infections. Increasing age is associated with decline in lung function, both in asthma and in those without asthma.1 29
Loss of lung function is accelerated by smoking by up to 50 ml per year,29 30 and there is an established dose–response relationship.29 31 32 The loss of lung function with smoking may even be greater in those with asthma, such that smokers with asthma can develop COPD. Importantly, quitting smoking slows the decline in lung function. In the Lung Health Study, the annual decline in FEV1 in people who quit smoking at the beginning of the 11 year study was 30 ml/year for men and 22 ml/year for women. Continued smoking led to a decline in FEV1 of 66 ml/year in men and 52 ml/year in women.30
BHR is present in between 10% and 20% of the population, and is frequently asymptomatic.2 33 The role of asymptomatic BHR in the development of asthma and COPD was investigated in the SAPALDIA (Study on Air Pollution and Lung Diseases in Adults) study. At baseline, 17% of the population had BHR to methacholine, and 50% of these were asymptomatic, giving a prevalence of asymptomatic BHR of 9%. Asymptomatic BHR was associated with an increased risk of developing newly diagnosed asthma, new symptoms of wheeze, chronic cough and a diagnosis of COPD after a 11 year follow-up period (table 3).34 Smoking led to an increased risk of developing BHR.35 36 This is an example of risk factor potentiation, where one risk for COPD positively interacts with another to potentiate the COPD risk.
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Table 3 Risk for the development of respiratory symptoms and for the presence of chronic obstructive pulmonary disease (COPD) related to asymptomatic bronchial hyper-responsiveness (BHR)34
BHR was also associated with an accelerated decline in lung function, and there was a significant interaction with smoking. There was a mean additional decline in FEV1 of 12 ml/year in current smokers and 11 ml/year in former smokers with BHR. Never-smokers with BHR also had an accelerated decline of 4 ml/year compared with asymptomatic participants without BHR. Thus active smokers with BHR were particularly at risk for the development of COPD. The mechanism is not known but may involve airway inflammation since induced sputum inflammatory markers were found to be increased in smokers with BHR.37
Several epidemiological studies have identified that there is accelerated decline in lung function as a result of asthma and this positively interacts with smoking. The factors associated with accelerated lung function decline in asthma include more severe BHR,38 adult-onset asthma,39 frequent severe exacerbations,40 persistent symptoms,41 baseline airflow obstruction38 and persistent elevation of exhaled NO in difficult to treat asthma.42 There is clear evidence of risk factor potentiation, as many of the risks for accelerated lung function decline in asthma are also risk factors for lung function decline themselves—that is, smoking, BHR and severe exacerbations. Interestingly, baseline airflow obstruction, which is a risk for accelerated lung function decline, may result from incomplete lung growth as a result of childhood asthma or other childhood exposures, and is an example where the pathways to COPD (box 1) potentiate each other.
The deficits in lung function in asthma seem to arise early in the course of the disease,43 44 and may be an effect of incomplete lung growth.43 In one study, abnormal lung function at age 26 in patients with asthma was related to male sex, BHR at age 9 years, early onset of asthma and reduced lung function by age 9 years.41
Both patients with asthma and those with COPD experience exacerbations of their disease. These are clinically significant events, frequently triggered by viral respiratory tract infection, and associated with quality of life impairment, loss of functional ability and increased healthcare utilisation. Recent data now show that disease exacerbations in both asthma and COPD45 46 (fig 7) can lead to accelerated loss of lung function. In asthma a longitudinal cohort study of patients with persistent asthma14 found a greater decline in FEV1 in those patients with frequent severe exacerbations. In a regression analysis, one severe exacerbation was associated with a 30 ml greater annual decline in FEV1. These results show that a severe asthma exacerbation is associated with accelerated FEV1 decline, to a similar degree as that seen with smoking and COPD. Another important observation was that the decline in FEV1 seen in infrequent exacerbators was not different from the population without asthma. This raises the possibility that modifying the exacerbation rate may prevent the onset of fixed airflow obstruction in asthma.
Annual change in forced expiratory volume in 1 s (FEV1) for patients with frequent (filled circles) and infrequent (open circles) exacerbations of chronic obstructive pulmonary disease (COPD). (Reproduced with permission from Thorax).
Childhood: risk factors for incomplete lung growth
Lung function in early adult life is a strong risk factor for the development of COPD. There is now evidence that poor lung function in infancy and childhood persists into adulthood, and that in utero events can modify airway function in early postnatal life. Stern et al studied lung function in infants soon after birth and found that poor airway function at that time was a risk factor for impaired adult lung function,45 suggesting that airway function throughout adult life may be determined during fetal development and the first few months of postnatal life.45 Maternal smoking adversely influences lung growth.46 In infancy there is an ∼15–20% reduction in airflow in children born to mothers who smoked during pregnancy.47 In addition, maternal smoking is associated with impaired fetal growth, and intrauterine growth retardation is itself associated with impaired airway function in infancy and later life.
Many of the risk factors for incomplete lung growth in childhood are similar to the risk factors for accelerated loss of lung function in adults, namely tobacco smoke exposure, asthma, BHR48 and exacerbations or respiratory infections. Additional risk factors include low birth weight, gender (lower in boys), nutrition and ethnicity.
Several longitudinal studies show that at the commencement of adulthood, lung function is lower in people with asthma than in those without (fig 6).29 41 43 Impaired lung function has been observed in up to 25% of children in the Childhood Asthma Management Program49 and in children with eosinophilic asthma.52 This suggests that there may be incomplete lung growth with asthma, and this can be another pathway to the development of impaired lung function in adulthood.
There is an established relationship between smoking and asthma, with smoking potentiating the effects of asthma on respiratory ill-health. Surprisingly, there appears to be bi-directionality in the relationship between smoking and asthma. Studies have shown unexpectedly higher smoking rates in some groups with asthma, such as adolescents and pregnant women. Longitudinal studies among adolescents have identified that asthma is a risk factor for starting smoking and becoming a regular smoker.50
Early life infections
There is emerging evidence of a role for early life infections leading to impaired lung function and modification of asthma risk. For example, Barker studied lung function in adult men and found an association between respiratory infection during infancy and reduced adult lung function.51 Other studies show that respiratory viral infection modifies BHR, which is a risk for impaired lung function. Of equal importance is the now well-established observation that impaired lung function often precedes a viral-induced wheezing illness in childhood and leads to an increased likelihood of wheezing when a child subsequently develops a respiratory infection.52 This suggests a complex relationship between childhood respiratory infection and subsequent lung growth, and the need for more detailed mechanistic studies.
These events can be studied successfully in dynamic model systems. Chlamydia infection has been associated with asthma and may both cause acute infection and then enter a state of persistent infection with episodic reactivation.53 Chlamydia infection is also prevalent, and exposure can occur not only via respiratory infection, but during birth infants could be exposed to maternal Chlamydia, leading to the potential for early life Chlamydia exposure. When the effects of neonatal Chlamydia infection are examined in models of allergic sensitisation, then profound changes are seen. Neonatal Chlamydia infection leads to impaired lung growth with abnormal airspace enlargement. When combined with allergic sensitisation, then adult BHR is enhanced by neonatal Chlamydia infection, and there is enhanced airway remodelling with increased airway goblet cells, and abnormal airspace enlargement.53
Expert Answers: What Is The Difference Between Asthma and COPD?
We asked our experts to answer this quesiton: What is the difference between COPD and asthma
Simply put, the difference between asthma and copd is that asthma is classified as a reversible lung disease and copd is classified as a chronic lung disease that is not fully reversible. Let me explain further. Asthma is defined as a condition where your airways swell and produce extra mucus which makes breathing difficult and causes coughing, chest tightness and oftentimes wheezing. Copd is a condition where there is chronic obstruction of airflow in the lungs that interferes with normal breathing and is not fully reversible, thus lung function decreases over time. Copd is an umbrella term that includes both chronic bronchitis and emphysema. Both asthma and copd can be managed under a doctor’s care.
Chronic Obstructive Pulmonary Disease (COPD) is a group of lung diseases that block airflow in the lungs. Included in this grouping are emphysema and chronic bronchitis. The blockage of airflow in the lungs makes it increasingly difficult to breathe. Many of the symptoms of COPD are similar to asthma symptoms.
Asthma is a chronic disease involving the airways in the lungs. These airways, or bronchial tubes, allow air to come in and out of the lungs. A main characteristic of asthma is that the airways are always inflamed. They become even more swollen and the muscles around the airways can tighten when something triggers the symptoms. This makes it difficult for air to move in and out of the lungs, causing symptoms such as coughing, wheezing, shortness of breath and chest tightness. Because asthma and COPD have a number of similarities, it can be difficult to distinguish between them. However, a physician can make a differential diagnosis by taking into account the patient’s symptoms and detailed medical history, providing a thorough physical examination, and reviewing the results of medical diagnostic tests (e.g. blood work, PFT’s, x-rays, etc.). Both COPD and asthma may cause shortness of breath and cough. A daily morning cough with mucous production is generally characteristic of COPD. Episodes of wheezing and chest tightness, especially at night, are more characteristic of asthma. The wheezing associated with asthma is considered to be reversible. In addition, patients with asthma are more likely to have allergies such as allergic rhinitis (hay fever) or atopic dermatitis (eczema). Other common symptoms of COPD include fatigue and frequent respiratory infections. COPD is almost always associated with a long history of smoking, while asthma occurs in non-smokers as well as smokers. Smoking can also make asthma worse; and smokers are particularly likely to suffer from a combination of both asthma and COPD. Although initially, it may take some time and effort, it is important to distinguish between COPD and
asthma when the patient first presents to a physician. The treatment for each disease is completely different, even though symptoms tend to be similar. It will be of great benefit for the patient to receive an accurate diagnosis and a subsequent appropriate treatment plan. It is therefore necessary to see a competent physician who can partner with you to manage the disease.
Both asthma and COPD are diseases that result in airflow limitation and shortness of breath due to airway narrowing and obstruction. However, there are a few differences between these two diseases. 1. Asthma is caused by chronic underlying airway inflammation that worsens due to exposure to asthma triggers, resulting in airway obstruction and asthma symptoms. COPD is caused by loss of lung tissue that causes air sacs to become dilated and airways to become chronically narrowed. It is also caused by chronic airway scarring resulting in airway narrowing. 2. Asthma is defined as being completely reversible with either time or treatment, while COPD is only partially reversible with time or treatment. This means that asthmatics have normal lung function and no (or minimal) shortness of breath between episodes, while COPDers may experience some decline in lung function and some shortness of breath between episodes, even on a good day. 3. Asthma is most often diagnosed in childhood, and COPD most often diagnosed after the age of 40. 4. Asthma generally does not get worse with age, although COPD gradually progresses over time. There is actually a condition called asthma/ COPD overlap syndrome, and this is where a person has a combination of both diseases. It is estimated that about 10-15% of asthmatics have this. Because it results in more severe asthma, it is sometimes defined as Severe Asthma.
Since many of the symptoms are similar, it can be difficult to distinguish between COPD and asthma. Ideally, both require lung function tests to diagnosis. In the classic asthma patient, airway constriction is reversible (with or without medication), whereas the in the person with COPD, airway obstruction is largely irreversible.
COPD is term used to describe a class of pulmonary diseases such as emphysema and chronic bronchitis. It is progressive and gets worse with age. Early diagnosis is imperative to maintaining lung function. Symptoms of COPD range from increased cough and mucous production to extreme shortness of breath and exercise intolerance. In general, COPD tends to manifest itself in adults that smoke or have smoked.
Asthma is characterized by bronchoconstriction that causes wheezing, airway inflammation, and hyper-sensitive airways. This, in turn, leads to coughing and shortness of breath. Asthma is noted for its intermittent symptoms that can be triggered by allergens, weather (both hot and cold), and exercise. The initial presentation of asthma is usually much younger than the onset of COPD.
Both tend to respond well to medications for the lungs, particularly bronchodilators and long term corticosteroids. With both conditions it’s very important to quit smoking and avoid any pollutants that irritate the lungs.
Both asthma and COPD are diseases of the airway that make it hard to breathe. They have similar symptoms; such as shortness of breath and coughing. Both are chronic. However, they are very different diseases. Asthma symptoms are caused when you breathe in a trigger. These symptoms can be “reversed” with medication. When you have chronic bronchitis or emphysema, the two diseases under the umbrella of COPD, the symptoms can be lessened by not reversed. Why? Because COPD means there is permanent damage or scarring to the lungs. However, asthma is episodic, meaning symptoms come and go. COPD is a progressive lung disease that worsens over time due to structural changes, or damage, to the airways. Triggers can also cause acute symptoms if you have COPD. It’s possible to have asthma-COPD overlap syndrome, when you have both diseases. Ask your health care provider for lung function testing to get the correct diagnosis and treatment plan.
Is Asthma considered part of COPD?
We started off with our definition of chronic obstructive lung disease, or COPD, by including the notion that it is a not reversible limitation of the flow of air. And we think of asthma as classically having reversibility and the ability to normalize or come close to normalizing the flow of air. So asthma is very much a disorder of lots of inflammation and very little damage, while chronic obstructive lung disease we think of the limitation and how the bronchial tubes are working as uncorrectable, completely, it can be improved, but it cant be fixed completely. And that some scarring, or the term we use is “remodeling” has occurred in the bronchial tubes.
I think it’s very important to understand emphysema, which is one of the forms of chronic obstructive lung disease, because it really is the form of chronic obstructive lung disease that involve the actual loss and destruction of functioning lung tissue. The air sacks are damaged, and the blood vessels in those air sacks may be damaged. The combination of bronchial tube disease, which is more likely to cause cough and mucus and wheezing, with emphyzema. Some combination of those two areas may be present more or less in any individual. You may have more of one and less of the other. You may have a lot of both. You may have a little of both, but that is another part that has to be considered as well.
We think now of what asthma has in common with chronic lung disease and that is the inflammation. That is one of the ways we intervene and manage a chronic obstructive lung disease. We also believe now, that if you have asthma and its not corrected, that this inflammation of the bronchial tubes and its never fixed, that it goes on for years and decades, that it can end up as chronic obstructive lung disease. So asthma and COPD not the same, but they do share common symptoms and it seems that one can become the other.
Chronic Obstructive Pulmonary Disease (COPD)
Chronic Obstructive Pulmonary Disease (COPD) refers to progressive lung diseases including emphysema, chronic bronchitis, and refractory (non-reversible) asthma. This disease is characterized by increasing breathlessness. COPD is a progressive and incurable disease, but with the right diagnosis and treatment, there are many things you can do to manage your COPD and breathe better. People can live for many years with this disease and enjoy life.
In Emphysema the tiny, delicate air sacs (alveoli) in your lungs are damaged. The walls of the damaged air sacs become stretched out and your lungs actually get bigger, making it harder to move your air in and out. Old air gets trapped inside the alveoli so there is little or no room for new air to go. In emphysema it is harder to get oxygen in and carbon dioxide (the waste product of your breathing) out.
Chronic bronchitis is an inflammation of the breathing tubes (bronchial airways) inside your lungs. Tiny hair-like structures (cilia) line your airways and sweep mucus up, keeping your airways clean. When cilia are damaged, they can’t do this, and it becomes harder for you to cough up mucus. This can make your airways swollen and clogged. These changes limit airflow in and out of your lungs, making it hard to breathe.
Refractory (non-reversible) asthma
Refractory (non-reversible) asthma is a type of asthma that does not respond to usual asthma medications. In an asthma attack, bronchial airways tighten up and swell. Medications can usually reverse this, opening up the airways and returning them to how they were before the asthma attack. In refractory asthma, medications cannot reverse the tightening and swelling of the airways.
Signs and Symptoms of COPD
- Increased shortness of breath
- Frequent coughing (with and without mucus)
- Increased breathlessness
- Tightness in the chest
What causes COPD?
Most cases are caused by inhaling pollutants; that includes tobacco smoking (cigarettes, pipes, cigars, etc.), and second-hand smoke. Fumes, chemicals and dust found in many work environments are contributing factors for many individuals who develop COPD. Genetics can also play a role in an individual’s development of COPD—even if the person has never smoked or has ever been exposed to strong lung irritants in the workplace.
How is COPD Diagnosed?
A spirometry test measures how well your lungs are working. It’s a simple and easy test that can help diagnose COPD. When you take the test, you will be asked to blow all the air out of your lungs into a mouthpiece connected to a machine known as a spirometer.
The machine will calculate two numbers: the amount of air you blow out in the first second, and the amount of air you blow out in 6 seconds or more. Your doctor will read the results.
A person may have Chronic Obstructive Pulmonary Disease but not notice symptoms until it is in the moderate stage. This is why it’s important to ask your doctor about taking a spirometry test.
When to see your doctor?
If you are a current or former smoker, have been exposed to harmful lung irritants for a long period of time, or have a history of Chronic Obstructive Pulmonary Disease in your family, speak to your healthcare provider. It’s easy to think of shortness of breath and coughing as a normal part of aging, but these could be signs of COPD. COPD can progress for years without noticeable shortness of breath. Ask your healthcare provider about ordering a spirometry test. Leaving symptoms misdiagnosed, untreated, or under treated may cause them to worsen faster than if they were treated with proper medication and therapy. To schedule an appointment with a CareMount Medical provider, book online at caremountmedical.com/247
What is the difference between COPD and Asthma?
A common concern of patients is the difference between chronic obstructive pulmonary disease (COPD) and asthma. Although a detailed comparison is beyond the scope of this article, one can consider basic differences between the two conditions. Both diseases are considered to be “obstructive” lung diseases, meaning that patients have difficulty exhaling completely between breaths. Obstructive lung diseases can be diagnosed by lung testing called spirometry. In this test, patients exhale forcibly into a machine which measures the amount of air they exhale in 1 second (Forced Expiratory Volume-1 or FEV1), and the total amount of air they exhale in a breath (Forced Vital Capacity or FVC). The machine then calculates a ratio of how much air was exhaled in the first second vs. the total amount of air exhaled in the breath, which is called the FEV1/FVC ratio. Said a different way, most patients will exhale 70% or more of their breath in the first second of exhalation. If they do not, they are considered to have a form of obstructive lung disease, such as asthma or COPD.
Do I have it?
Asthma typically, although not universally, presents at a younger age ( Chronic Obstructive Pulmonary Disease (COPD) typically presents later in life (over age 40), and is also associated with shortness of breath, coughing, wheezing, and chest tightness. COPD more commonly has additional symptoms of sputum production and shortness of breath requiring short term oxygen use. Like asthmatics, patients may feel increased symptoms when exposed to triggers such as fumes, or with lung infections. Also, like asthmatics, patients with COPD will have a reduction in their ability to exhale, and will show reductions in airflow when tested with spirometry. However, unlike asthmatic patients, COPD patients will not be able to completely correct their lung function even with treatment. COPD is also associated with permanent structural changes in lung structure, which may be seen on radiological studies such as CT scans. Emphysema is one such permanent change, and is a condition of destruction of alveoli, which are the parts of the lung where oxygen is absorbed into the blood stream. Emphysema is often seen in the setting of COPD, and is rarely seen with asthma. Tobacco use is by far the most common cause for COPD in developed countries, but other causes for COPD do occur such as genetic conditions. Alpha-1 antitrypsin deficiency (A1AT) is an example of a genetic condition which causes COPD in patients. This condition can be diagnosed with a simple blood test, and treatment is available to allow patients with A1AT to maintain their lung function.
Can it be treated?
Importantly, asthma and COPD can co-exist in patients, and it can be difficult to sort out whether patients have one or both conditions. Allergist/immunologists are experts in this area of medicine, and are commonly consulted to help with the diagnosis and treatment of these conditions. Allergists can rely on spirometry testing as discussed, or may order additional lung testing, such as full pulmonary function tests (PFTs). Fortunately, both asthma and COPD have great treatments to allow patients to breathe at their best. To learn more, consult your trusted Allergy Partners physician or visit allergypartners.com.
By Dr. Todd Cross
Allergy Partners of Western North Carolina