COPD risk factors: what raises the risk and what lowers it

What COPD is

COPD is a group of lung diseases that make it hard to breathe and get worse over time (MedlinePlus). Less air flows in and out of the airways because the airways and air sacs lose their stretch, the walls between air sacs are destroyed, the airway walls become thick and inflamed, or the airways make extra mucus and clog (NHLBI). The two main types are emphysema and chronic bronchitis, and most people with COPD have both (MedlinePlus).

The cause is usually long-term exposure to irritants that damage the lungs and airways (MedlinePlus). There is no cure, but treatments can help with symptoms and slow the disease (MedlinePlus).

Risk factors that raise the risk

• Smoking. This is the main risk factor. Three out of four people who have COPD smoke or used to smoke (NHLBI). Pipe, cigar and other types of tobacco smoke can also cause COPD, especially if you inhale them (MedlinePlus).
• Secondhand smoke. Breathing in smoke from other people smoking is one of the lung irritants that raise the risk (NHLBI).
• Workplace dust and chemical fumes. Long-term exposure to chemical fumes and dust from the environment or workplace raises the risk (NHLBI). The US Preventive Services Task Force notes that fumes, dust and chemicals at work are thought to contribute to about 15% of cases (USPSTF 2022).
• Air pollution and smoke from indoor fuels. Long-term exposure to air pollution, and smoke from home cooking and heating fuels without ventilation, raise the risk (NHLBI).
• Alpha-1 antitrypsin (AAT) deficiency. This condition runs in families. If you are born with it, smoking or long-term exposure to fumes or dust can lead to lung damage and COPD, and it can raise the risk of COPD at a younger age (NHLBI). MedlinePlus says it rarely plays a role in causing COPD (MedlinePlus).
• Family history. People who have a family history of COPD are more likely to develop the disease if they smoke (NHLBI).
• Asthma. People who have asthma have more risk of developing COPD than people who don't, but most people with asthma will not get COPD (MedlinePlus).
• Age. Age may play a role if you have other risk factors, such as smoking. Most people who have COPD are at least 40 years old when symptoms begin (NHLBI).
• Lung growth early in life. Conditions that affect the lungs before birth or in childhood, such as smoking in pregnancy or childhood asthma, can raise the risk. Air pollution can also limit the growth of a child's lungs (NHLBI).
• Infections. Conditions such as HIV and tuberculosis can raise the risk (NHLBI).
• Other possible factors. NHLBI lists vitamin D deficiency and changes in CHRNA genes as other possible genetic risk factors, and NHLBI-supported research found that having smaller airways for your lung size can also raise the risk, even in people who do not smoke (NHLBI).

Women and men

COPD affects both men and women, but may affect them differently. The reason is not known; women have smaller lungs than men, which may make their airways more prone to narrowing when exposed to irritants (NHLBI).

Which ones you can change

The best way to prevent COPD is to quit smoking or, if you don't smoke, not to start. Also try to avoid lung irritants such as air pollution, chemical fumes, dust and secondhand smoke (NHLBI). Quitting is the most important step to help slow COPD if you already have it. Using e-cigarettes or vaping to try to quit is not a good idea for smokers who have COPD (NHLBI). NHLBI points to the National Cancer Institute's Smoking Quitline at 1-877-44U-QUIT (1-877-448-7848) for free help (NHLBI).

Smoking also raises the risk of lung cancer; see lung cancer risk factors.

Alpha-1 antitrypsin deficiency

AAT is a protein made in the liver that helps protect the lungs. Without enough of it, the lungs are more easily damaged by smoking, pollution or dust (NHLBI). It is inherited, so it cannot be prevented. It can happen to anyone of any race or ethnicity, but it is more common in white people of Northern European backgrounds (NHLBI). When symptoms appear, they usually start between ages 20 and 50, and people are often first diagnosed with asthma (NHLBI).

NHLBI suggests talking to your provider if a family member has AAT deficiency, or was a smoker diagnosed with COPD between ages 40 and 50, or if you have an ongoing cough, shortness of breath, wheezing or liver disease (NHLBI).

Early symptoms to report

At first, COPD may cause no symptoms or only mild ones (NHLBI). Common symptoms include (NHLBI) (MedlinePlus):

• An ongoing cough, or a cough that produces a lot of mucus, sometimes called a smoker's cough; this is often the first symptom
• Shortness of breath, especially with physical activity
• Wheezing, or a whistling or squeaky sound when you breathe
• Chest tightness or heaviness
• Fatigue or extreme tiredness

Not everyone with these symptoms has COPD (NHLBI). As soon as you notice symptoms in yourself or a loved one, make an appointment with a provider and don't wait for them to become serious (NHLBI).

Call 911 if someone with breathing problems has a hard time catching their breath or talking, has lips or fingernails that turn blue or gray, is not mentally alert, has a very fast heartbeat, or their usual treatment is not working (NHLBI).

Is there a screening test?

There is no routine screening for COPD; if you have risk factors, talk to your healthcare provider (NHLBI). For adults without symptoms, the US Preventive Services Task Force recommends against screening, and that advice does not apply to people with a chronic cough, phlegm, shortness of breath or wheezing (USPSTF 2022). The COPD screening check explains what it means for you.

Common questions

Can I get COPD if I never smoked?

Yes. Other lung irritants, alpha-1 antitrypsin deficiency, childhood lung conditions and infections can raise the risk (NHLBI), and people with smaller airways may develop COPD-like symptoms later in life even if they do not smoke (NHLBI).

Does asthma turn into COPD?

Asthma raises the risk, but most people with asthma will not get COPD (MedlinePlus).

What is the most important change I can make?

If you smoke, quitting. Smoking is the leading cause of COPD (NHLBI).