Chronic obstructive pulmonary disease (COPD) is the name given to forms of serious lung conditions that affect the airways. It makes the airways become narrower, obstructed, and inflamed, making it difficult to breathe. One of the main causes of COPD is smoking, or exposure to second-hand smoke, which can have a devastating effect on lung function. 

Why is smoking a leading cause of COPD?

Smoking involves breathing in cigarette smoke, which goes into the lungs and causes damage. Up to 70 of the chemicals contained in cigarette smoke are known to be carcinogens (substances that promote cancer), and they can damage your airways and the small sacs of air – called alveoli – that are found in your lungs.   

In addition to causing COPD, smoking causes numerous other health issues, affecting your overall health, your immune system, and your quality of life and increasing your risk of stroke, coronary heart disease, and numerous types of cancer. If you’re a smoker, consider speaking to your doctor about quitting smoking and other ways to improve your general health.

If you smoked during your teenage years or were exposed to secondhand smoke during childhood, you may suffer from slow lung growth and development. This can also increase your risk of COPD when you’re an adult. 

How many smokers get COPD?

In the US, statistics show that smoking causes 79% of all cases of COPD. It’s a similar case in the UK, where around a quarter of deaths among smokers are caused by COPD. 

COPD is a long-term condition that affects about 251 million people worldwide. Figures even suggest that by 2030, COPD could become the third leading cause of death in the world. 

Do all smokers have COPD? 

Not all smokers – even those who smoke heavily – have COPD. In fact, research shows that nearly one-third of cases occur in people who’ve never smoked. That’s because other factors can be involved in the development of COPD. 

Other causes of COPD

COPD develops as a result of long-term damage to the lungs that causes them to become narrowed, inflamed, and obstructed. Aside from smoking, other causes include: 

  • A family history of chronic lung disease 
  • Exposure to air pollution, dust, fumes, or chemicals
  • Frequent childhood chest infections that left the lungs scarred 
  • Age – COPD is more likely to develop after the age of 35.

A rare genetic condition called alpha-1-antitrypsin deficiency affects about one in 100 people and makes them more susceptible to COPD at a younger age, particularly if they smoke. Alpha-1 antitrypsin is a substance that normally protects the lungs, and without it leaves them more vulnerable to damage. 

Recent research also suggests that having small airways relative to the size of the lungs could leave people predisposed to a lower breathing capacity and an increased risk of COPD. 

What happens if you smoke with COPD?

If you have been diagnosed with COPD, your family doctor will recommend you stop smoking. This gives you the best chance of treating and managing your COPD symptoms. One study found that stopping smoking significantly reduced the risk of hospitalization and death for COPD patients, and ex-smokers had much better outcomes than those who continued to smoke after being diagnosed with COPD

If you aren’t able to quit your tobacco habit or don’t want to stop smoking, you may find that smoking exacerbates your COPD symptoms and causes more flare-ups. This can increase your risk of being admitted to the hospital for additional treatment, affect your quality of life, and lower your life expectancy.

How long can you live with COPD and still smoke?

It’s hard to predict exactly how long you can live with COPD and still smoke. It depends on a multitude of factors, including what stage your COPD is at, any other health issues you have, and how much you smoke. 

Numerous studies have shown a definite increase in the risk of mortality in people with COPD who smoke compared to those who don’t. Studies suggest that those with stage one or two (mild and moderate) COPD who smoke lose a few years of life expectancy at the age of 65. For those with stages three or four (severe and very severe) COPD, they lose from six to nine years of life expectancy due to smoking. This is in addition to the four years of life lost by anyone who smokes. 

If you have any questions about how your COPD smoking habit will affect your life expectancy, speak to your doctor. 

How to prevent COPD

One of the best ways of preventing COPD is not to smoke or be exposed to secondhand smoke, as it can cause a lot of damage to your airways and lungs. 

But as COPD can sometimes be caused by other factors, such as genetics and childhood lung infections, it’s not always easy to prevent every single case. 

Whatever the circumstances, an early diagnosis and appropriate treatment regime for your needs can prevent further damage from being caused to your lungs.

How to treat COPD

Sadly, there is no cure for COPD as the lung damage that has already occurred cannot be reversed. However, the disease can be managed and treated to help prevent further damage and improve your symptoms and quality of life. 

The treatments you’ll need will depend on your stage of COPD and how COPD is affecting you. 


American Lung Association – Learn About COPD.

ASH – Smoking and respiratory disease

BMJ Best Practice – Chronic Obstructive Pulmonary Disease (COPD)

British Lung Foundation – Chronic Obstructive Pulmonary Disease (COPD) statistics

British Thoracic Society – COPD

Chen CZ, Shih CY, Hsiue TR, Tsai SH, Liao XM, Yu CH, Yang SC, Wang JD. Life expectancy (LE) and loss-of-LE for patients with chronic obstructive pulmonary disease. Respir Med. 2020 Oct;172:106132. doi: 10.1016/j.rmed.2020.106132. Epub 2020 Aug 29. PMID: 32905891.

HHS – Health consequences of smoking, Surgeon General fact sheet. 

Josephs L, Culliford D, Johnson M, et al. Improved outcomes in ex-smokers with COPD: a UK primary care observational cohort study. European Respiratory Journal May 2017, 49 (5) 1602114; DOI: 10.1183/13993003.02114-2016

Lamprecht B, McBurnie MA, Vollmer WM, et al. COPD in never smokers: results from the population-based burden of obstructive lung disease study. Chest. 2011;139(4):752-763. doi:10.1378/chest.10-1253

NHS – Chronic obstructive pulmonary disease – causes

NICE – Chronic obstructive pulmonary disease in adults

Qaseem A, Wilt TJ, Weinberger SE, Hanania NA, et al. American College of Physicians; American College of Chest Physicians; American Thoracic Society; European Respiratory Society. Diagnosis and management of stable chronic obstructive pulmonary disease: a clinical practice guideline update from the American College of Physicians, American College of Chest Physicians, American Thoracic Society, and European Respiratory Society. Ann Intern Med.

Shavelle RM, Paculdo DR, Kush SJ, Mannino DM, Strauss DJ. Life expectancy and years of life lost in chronic obstructive pulmonary disease: findings from the NHANES III Follow-up Study. Int J Chron Obstruct Pulmon Dis. 2009;4:137-148. doi:10.2147/copd.s5237

Smith BM, Kirby M, Hoffman EA, et al. Association of Dysanapsis With Chronic Obstructive Pulmonary Disease Among Older Adults. JAMA. 2020;323(22):2268–2280. doi:10.1001/jama.2020.6918 

WHO – Chronic respiratory diseases – causes of COPD