Cannabis and Lung Health: What Happens to Your Lungs?

                

Smoking cannabis can harm the lungs. Like tobacco smoke, cannabis smoke contains many of the same toxic chemicals, irritants, and cancer-causing substances that are created when plant material is burned. These substances can damage the airways and lungs over time.

Regular cannabis smoking is associated with respiratory symptoms and lung changes that can affect breathing and overall lung health.

How smoking cannabis affects the lungs

Regular cannabis smoking has been linked to:

  • Chronic cough
  • Increased mucus and phlegm production
  • Wheezing
  • Shortness of breath
  • Chest tightness
  • Chronic bronchitis (inflammation of the airways)

What can cannabis-related lung damage look like on a CT scan?

A CT (computed tomography) scan provides detailed images of the lungs and can identify structural changes caused by smoking.

A Canadian study conducted by researchers at The Ottawa Hospital and the University of Ottawa compared CT scans from cannabis smokers, tobacco-only smokers, and non-smokers. Researchers found higher rates of:

  • Emphysema
  • Airway inflammation
  • Bronchial wall thickening
  • Bronchiectasis (permanent widening and damage of airways)
  • Mucoid impaction (airways blocked with mucus)

Researchers cautioned that additional studies are needed, but the findings raise concerns about the effects of cannabis smoking on lung health.

Sources

  • Health Canada. Cannabis Health Effects. Government of Canada. [canada.ca]
  • Canadian Centre on Substance Use and Addiction (CCSA). Clearing the Smoke on Cannabis: Highlights. 2022. [ccsa.ca]
  • American Lung Association. Marijuana and Lung Health. 2024. [lung.org]
  • Murtha L, Sathiadoss P, Salameh JP, McInnes MDF, Revah G. Chest CT Findings in Marijuana Smokers. Radiology. 2023;307(1). University of Ottawa/The Ottawa Hospital study. [pubs.rsna.org]
  • Radiological Society of North America (RSNA). Emphysema More Common in Marijuana Smokers than Cigarette Smokers. 2022. [rsna.org]
  • University of Ottawa Faculty of Medicine. Marijuana Smokers Show Higher Rates of Emphysema, Airway Diseases than Cigarette Smokers. 2022. [uottawa.ca]