What to know about asthma, COPD, and how they may overlap

If you feel short of breath while exercising, or you’re prone to fits of coughing, you may be wondering if asthma or chronic obstructive pulmonary disease (COPD) could be the cause. Asthma and COPD are often confused or lumped together because they share some of the same symptoms.

“Both conditions cause wheezing and shortness of breath,” says Nicholas Roy, DO, a pulmonologist at Inspira Pulmonary Vineland in Vineland, New Jersey. “But not everyone who wheezes has asthma, nor do they necessarily have COPD—it takes a little more investigating to figure out which condition it is.”

Here are some key similarities between the two conditions and how to tell them apart.

What are asthma and COPD?

Here are some of the key features of asthma and COPD.

Asthma

Asthma is a chronic lung disease that often appears during childhood. It may be reversed over time, but many people have asthma for life.

“It causes airway tightening, inflammation, and constriction in the lungs. The small airways actually narrow, leading to shortness of breath, coughing, and wheezing,” says Dr. Roy.

These symptoms become especially severe during asthma attacks. Asthma attacks may be brought on by triggers such as allergies, exercise, irritating fragrances, poor air quality, and lung infections. Attacks can be life-threatening, but they’re usually treatable at home with rescue inhalers like albuterol.

COPD

“COPD is a group of chronic lung diseases, which are often caused by smoking and don’t typically appear until after age 40. These diseases include chronic bronchitis and emphysema,” says Roy.

• Chronic bronchitis is an ongoing cough, which produces large amounts of mucous.
• Emphysema involves damage and scarring of tiny air sacs in your lungs, called alveoli. When alveoli are destroyed, it’s harder for your lungs to take in oxygen and release carbon dioxide.

While smoking is the leading cause of COPD, the condition is also linked to air pollution, occupational exposures like asbestos, and an inherited condition called alpha-1 antitrypsin deficiency. This condition affects how your body produces a protein that protects the lungs.

There are treatments for COPD, but there’s no known cure. Many of the same triggers that cause asthma attacks could also lead to COPD exacerbations, also known as symptom flare-ups. Exacerbations can be serious and require a hospital stay. With each flare, COPD tends to become a little worse.

Are COPD and asthma diagnosed the same way?

Some of the same tests are used to diagnose both asthma and COPD. For example, your lung specialist will ask about your symptoms, listen to your heart and lungs, and have you complete a pulmonary function test (PFT).

A PFT involves taking a deep breath, and then exhaling as long and hard as you can into a special tube. The tube is attached to a computer, which measures your lung strength and capacity, or the amount of air you’re able to exhale. If your PFT score suggests lung issues, your healthcare provider (HCP) will give you an inhaled medication to help open up your airways, and then ask you to redo the test. People with asthma typically score better after taking the medication, while those with COPD show little or no improvement.

Your lung specialist may also do blood tests, as well as a chest X-ray, to determine if another condition like pneumonia could be causing your symptoms.

Are both conditions preventable?

COPD is largely preventable since smoking causes about 75 percent of cases. You can’t prevent asthma, but you can limit the number of attacks you experience by:

• Avoiding triggers
• Staying up to date with your annual flu shot and vaccinations against respiratory syncytial virus (RSV) and COVID-19
• Taking your daily, or maintenance, inhalers and oral medications

Smoking can’t cause asthma, but it can trigger attacks, make it harder to fight lung infections, and increase your risk of developing COPD.

“People with asthma are actually more likely to damage their lungs with cigarette smoke,” says Roy. “It puts them at a slightly higher risk for COPD than the average person.”

Can asthma cause COPD?

Asthma and COPD are two separate conditions. Asthma is a disease in which the lungs become inflamed, often due to triggers or allergies. One of the hallmarks of asthma is its transient nature—the symptoms come and go. COPD is caused by permanent damage to the lungs. COPD’s symptoms are persistent, meaning they stick around and progress to become worse over time.

Since they’re two separate conditions, one can’t cause the other. However, that isn’t a completely hard-and-fast rule. People with severe asthma, also known as refractory asthma, whose symptoms don’t improve with treatment, may develop damage to their lungs from their frequent asthma attacks. This means they could be at higher risk of developing COPD.

How do asthma and COPD overlap?

When someone is diagnosed with both asthma and COPD, or has symptoms of both, they may be described as having asthma-COPD overlap syndrome (ACOS). The term ACOS doesn’t refer to a new disease but is instead just a way for HCPs to identify the mix of symptoms of both diseases.

The technical definition of ACOS is “persistent airflow obstruction with features of asthma.” Someone with ACOS has a chronic and progressive difficulty with breathing, and at the same time experiences periodic triggered asthma attacks.

How asthma and COPD are treated

Quitting smoking is the number one treatment for COPD and a key part of controlling asthma symptoms. For help quitting tobacco:

• Call the national Smokefree Hotline at 1-800-QUIT-NOW (1-800-784-8669)
• Reach out to an addiction specialist for personalized help

Asthma and COPD also share some, but not all, medications.

“There's often a crossover between inhaler therapies for both conditions,” explains Roy. “Inhalers include bronchodilators, or drugs that help open up the airways to allow better air flow in and out. Both conditions may also require steroid inhalers, although people with asthma tend to respond a little better to steroid treatments. This is a major reason why there's often confusion between the two conditions.”

Visit your lung specialist at least once a year to determine which medications are right for you and to update your medication list as symptoms change. Individuals with both asthma and COPD often need a combination of inhalers, which may vary from season-to-season or depending on how advanced your condition is. You can use Sharecare’s find a doctor tool to make an appointment with a lung doctor near you.