COPD Causes and Risk Factors

Medically Reviewed by Nayana Ambardekar, MD on April 11, 2023
3 min read

Chronic obstructive pulmonary disease, or COPD, is an ongoing lung disorder that makes it hard to breathe.

The main cause of COPD is smoking, but you don’t have to be a smoker to get it. Other things can lead to this condition, which leaves you feeling short of breath.

Learn more about what causes it, who has the greater odds of getting it, and how you can lower your chances.

COPD is most likely to result from:

  • Cigarette smoke: This is by far the most common reason people get COPD. You can also get it from tobacco products, such as cigar and pipe smoke, especially if you breathe in the smoke.
  • Secondhand smoke: Even if you aren’t a smoker, you can get COPD from living with one.
  • Pollution and fumes: You can get COPD from air pollution. Breathing in chemical fumes, dust, or toxic substances at work can also cause it.
  • Your genes: In rare cases, people with COPD have a defect in their DNA, the code that tells your body how to work properly. This defect is called “alpha-1 antitrypsin deficiency,” or AAT deficiency. When you have this, your lungs don't have enough of a protein needed to protect them from damage. This can lead to severe COPD. If you or a family member had serious lung problems -- especially at a young age -- ask your doctor about testing for AAT deficiency.
  • Asthma: Poorly controlled asthma can raise the risk for developing COPD.


Things that can make you more likely to get COPD include:

  • Smoking: This is the most common cause of COPD.
  • Asthma: Your chances are even higher if you have asthma and you smoke.
  • Age: Most people are 40 or older when their symptoms start up.
  • Certain jobs: If your job puts you around dust, chemical fumes, or vapors, your lungs can get damaged. Damage can also come from prolonged exposure to air pollution.
  • Infections: If you had lots of respiratory infections in childhood, you have a greater chance of COPD in adulthood.


Inside your lungs are tiny sacs called alveoli. They fill up like balloons every time you take a breath. The oxygen in these sacs passes into your bloodstream, and then your lungs push out the stale air.

When you have COPD, your lungs don't work as they should. Long-term irritation from smoke or other pollutants can damage them for good.

When this happens, the walls between the alveoli break down. Your airways get swollen and clogged with mucus. It becomes harder to push out the stale air. You don't get enough fresh oxygen with each breath.

In most cases, this happens very slowly. The symptoms may come on over time. It may be years before you even notice them.

You can't heal the damage that has already happened in your lungs. But you can make changes to slow down the damage or stop it from getting worse.

  1. Don't smoke. This is the best way to prevent COPD or slow it down if you already have it. If you don't smoke, don't start. If you smoke, quit. Ask your doctor, family, and friends to help.
  2. Avoid breathing in things that bother your lungs. As much as possible, stay away from fumes, toxins, secondhand smoke, and dust.
  3. Watch out for colds, viruses, and infections. If you have COPD, even a common cold can lead to severe problems. During cold season, wash your hands well and often. Use hand sanitizer if you cannot wash your hands. Try not to be around people who are sick.
  4. Get vaccines. Protect your lungs against the flu and pneumonia.
  5. Ask your doctor about being tested for AAT deficiency. A blood test can find this type of COPD that you get from your parents at birth. It isn’t common, but if you have serious lung symptoms with no clear cause like smoking, your doctor may check. You may also need testing if you get emphysema (a type of COPD) before age 46 or have a family member with AAT deficiency. Medicines as well as other treatments and lifestyle changes can keep you breathing easier if you do have COPD.