There Are Three Causes of COPD.

Smoking is the main cause.

A smoker is at least 10 times more likely to die of COPD than a nonsmoker. What's more, tobacco smoke causes up to 90% of all COPD deaths. This includes exposure to secondhand smoke. So, if you're a smoker, you can see why it's important to quit.

Pollutants are also to blame.

Another cause is indoor and/or outdoor pollutants.
If you are exposed to toxic chemicals and pollutants at
work, you may be at higher risk for COPD.

A rare genetic condition contributes to some cases.

COPD can also result from a rare genetic disorder that causes low levels of a protein called Alpha-1 antitrypsin. And it's called Alpha-1 antitrypsin deficiency. It's also known as Alpha-1. This condition is inherited from your parents. In addition to severe lung disease, Alpha-1 can also cause liver disease. A simple blood test can show if you have Alpha-1.