Medically reviewed by
J. Gray Norris, MD
People often mistake asthma for COPD, or vice versa. It is understandable why. These chronic health conditions share many similar symptoms, both affect the respiratory system, and both tend to present with other underlying health conditions (comorbidities).
But while they can be similar in presentation, COPD and asthma have several distinct qualities, as well. Being able to identify these distinct qualities is essential for confirming an accurate diagnosis and—importantly—ensuring that you or your loved one gets the correct treatment.
Key Takeaways
- Chronic obstructive pulmonary disease (COPD) and asthma are distinct conditions, but they share similar symptoms and are often mistaken for each other.
- COPD affects the way a person breathes because of inflammation and narrowing of large airways in the lungs, damage to the lung’s air sacs, or both. Asthma affects the way a person breathes due to inflammation and narrowing of small airways in the lungs.
- The prevalence of both COPD and asthma is increasing, and a growing number of patients are presenting with both conditions, a phenomenon doctors are now calling asthma-COPD overlap (ACO).
- Despite having similar symptoms and presenting with similar comorbidities, COPD and asthma generally have different causes, triggers, treatments, and outcomes. COPD is usually preventable, and smoking tends to be the main cause. Asthma’s causes aren’t always known, but it is important to note many people with asthma also have allergies. These tend to go together so it is important to understand this when treating asthma. A trained allergist can treat both asthma & allergies effectively together.
- Asthma is generally easier to treat than COPD, but in severe cases both asthma and COPD can lead to life-threatening complications.
Defining Asthma vs COPD
Chronic obstructive pulmonary disease (COPD) is a term used to describe conditions that disrupt (obstruct) the way air flows in and out of the lungs. Two main types of COPD exist:- Chronic bronchitis: inflammation, swelling, and irritation of the larger tubes (bronchi) that carry air to and from the air sacs in your lungs, which leads to a build-up of mucus and narrowing inside the tubes & causes a decrease in airflow.
- Emphysema: damage to the air sacs (alveoli) inside the lungs that causes them to become weak and dysfunction; eventually they may rupture, leading to fewer larger air sacs instead of many tiny ones.
A Condition to Know: Asthma-COPD Overlap (ACO)
We’ve already learned that asthma and COPD are considered two distinct diseases (with COPD being further subdivided into chronic bronchitis and emphysema). This is important to know because often asthma and COPD have different clinical courses and treatments. But, doctors and researchers are discovering that an increasing number of patients present with both conditions, leading to a new clinical presentation known as asthma-COPD overlap (ACO). According to the American Lung Association, ACO is often described as “persistent airflow obstruction with features of asthma.” There is a great deal of scientific interest right now about ACO. This is partly because experts project that the number of people diagnosed with ACO will increase in the coming years, giving the rising prevalence of both COPD and asthma. People with ACO also appear to face more severe and frequent exacerbation of their symptoms. Unfortunately, because ACO is a newly described phenomenon, we don’t know yet what the best or most research-supported interventions are. No single medication or treatment has been identified for this disorder. Right now, doctors typically prescribe other medications already used to treat asthma or COPD to help alleviate symptoms associated with ACO. Hopefully, the medical community will have more clarity about this condition, including how to diagnose and treat it properly, within the coming years.Exploring the Key Differences and Similarities Between Asthma and COPD
When looking at asthma vs COPD, you start to see a lot of similarities and differences that are helpful for both patients and doctors to know.Asthma and COPD Causes
COPD develops when a person has chronic, long-term exposure to irritants that damage their lung cells and tissues. Cigarette smoke is the main culprit, and the majority of people with COPD are current or former smokers. However, as many as 1 in 4 people with COPD have never smoked, according to the CDC. We do know that COPD can also be caused by chronic exposure to secondhand smoke or chemical fumes, and dust. As noted by the National Heart, Blood, and Lung Institute, an extremely rare genetic disorder called alpha-1 antitrypsin deficiency may also increase the risk or severity of COPD in some people. We don’t know exactly what causes asthma to happen nor why some people develop it while others don’t. Asthma tends to run in families, so it seems likely that genetics play a role, but other factors, including a history of respiratory infections in infancy, may increase the risk of asthma. One type of asthma, known as allergic asthma, develops when a person’s immune system overreacts to a substance in the environment that should not normally cause problems.Asthma and COPD Triggers
A variety of factors in and around you can trigger a temporary flare-up of asthma or COPD symptoms. We usually call these asthma attacks or COPD exacerbation, respectively. Cigarette smoke and other airborne pollutants may trigger both asthma and COPD flare-ups. However, asthma attacks are more commonly triggered by other substances, including dust, mites, mold spores, pet dander, pollen, and sometimes food additives. These substances can trigger an over-the-top immune response, leading to the hallmark symptoms of airway inflammation and constriction. For people with COPD, an exacerbation of their symptoms is usually triggered by illnesses like the common cold or a bacterial infection. Stress, doing too much activity, being worn down, or even changes in the weather may also trigger a COPD exacerbation.Asthma and COPD Symptoms
Asthma and COPD share several signs and symptoms, which can be virtually indistinct from one condition to the other. These include:- Shortness of breath
- Tightness in the chest
- Coughing
- Intolerance to exercise
- Wheezing, which sounds like a whistle or squeak in the chest
- Anxiety and elevated heart rate during symptom exacerbation
- Severe trouble with breathing or speaking.
- A sudden bluish or purplish discoloration of the fingernails or lips (acute hypoxia).
- Decreased mental alertness.
- Rapid heartbeat.
- Symptoms that don’t get better even with the recommended treatment.
Asthma and COPD Diagnosis
Doctors often use similar tests and measures to diagnose COPD, asthma, or related conditions. Common diagnostic interventions include a physical exam and history, lung or pulmonary function tests, chest X-rays, and arterial blood gas tests. If your doctor suspects that your symptoms are caused by asthma, he or she may also run allergy tests to identify the environmental substances (allergens) triggering your condition. One key difference in diagnosis for these two conditions is that asthma can occur at almost any age, and it’s often diagnosed in children. But COPD is typically diagnosed in people over the age of 40. When diagnosing asthma, doctors often classify a person’s condition by severity: these include mild intermittent, mild persistent, moderate persistent, and severe persistent. COPD can also be classified into four different types or stages, depending on severity, ranging from stage I (early) through stage IV (very severe).Asthma and COPD Treatments
The best treatment for people with COPD and asthma depends on several factors unique to the individual, including the stage and severity of their disease, their overall health status, and their lifestyle. For COPD, common treatments include medications that open the large airways inside the lungs (called bronchodilators), smoking cessation, and oxygen therapy in advanced stages. For asthma, common treatments include corticosteroids, short-acting beta-agonists like albuterol, and anticholinergic drugs for severe attacks. The main approach to asthma management is to reduce the severity and frequency of asthma attacks, and provide fast-acting relief in the event of an acute or severe flare-up. Lifestyle strategies, including the avoidance of known lung irritants or environmental triggers, are also essential for both asthma and COPD management. You might see both people with COPD and asthma using inhalers, although they don’t always contain the same types of medications.Comorbidities
Other underlying health conditions tend to occur with asthma and COPD, including high blood pressure, insomnia, depression, stomach ulcers, cancer, migraine headaches, and sinus inflammation. People with asthma and especially COPD may struggle with mobility and have a hard time remaining physically active. It’s also been suggested that obesity can make asthma and COPD worse. Untreated and/or severe cases of asthma and COPD can also lead to serious or even life-threatening complications.Outlook and Prognosis
Diagnosis and treatment for both COPD and asthma are getting better, which means people are living longer and more active lives with either (or both) conditions. However, the general prognosis and outlook for asthma vs COPD can be quite different. While neither condition is curable, asthma is usually easier to treat. Asthma can be  well-managed with individualized treatment that a person may experience rare or even no symptoms of their disease. COPD is progressive, meaning that it tends to get worse over time. Symptoms can be managed in COPD, but a person’s breathing and lung function never really returns to “normal.” Living with either condition requires that a person has:- The medical support they need from professionals include doctors, mental health counselors, and physical therapists.
- Healthy lifestyle habits, including activity pacing, nutritious diets, and a regular physical activity routine that is appropriate to their ability level.
- An understanding of what causes their symptoms to flare-up and what to do if their symptoms become severe.
