Lung Recovery After Quitting: Health Canada Timeline
Key takeaways
Health Canada says the airways start to relax between 2 weeks and 3 months after your last cigarette, and coughing decreases between 1 and 9 months. Some damage, such as emphysema, is irreversible, but quitting is the most effective way to stop further lung damage.
This is general information from Health Canada, not medical advice. A cough that lasts, blood in your phlegm or breathlessness needs a clinician, whether or not you have quit.
How long do lungs take to recover after quitting smoking?
Health Canada’s quitting timeline puts the first lung changes between 2 weeks and 3 months: the airways relax and you can breathe easier. Between 1 and 9 months, coughing decreases. The page gives ranges, not a finish line, so a person who quit six weeks ago and still coughs is not behind schedule.
What changes in the first day?
Two things happen before the lungs themselves change. After 20 minutes, blood pressure returns to about the level it was before your last cigarette. After 8 hours, carbon monoxide in the blood falls to a normal level. Carbon monoxide crowds oxygen out of the blood, so this is the first step toward easier breathing.
Lung recovery timeline from Health Canada
| After quitting | What Health Canada lists |
|---|---|
| 20 minutes | Blood pressure back to about pre-cigarette level |
| 8 hours | Carbon monoxide in the blood back to normal |
| 2 weeks to 3 months | Airways relax, breathing is easier |
| 1 to 9 months | Coughing decreases |
| 10 years | Lung cancer risk is about half |
The full list, including heart and other cancer milestones, is on our quitting timeline.
Does the damage from smoking reverse?
Some of it does not. Health Canada’s page on chronic obstructive pulmonary disease defines emphysema as the gradual and irreversible damage of lung tissue and says COPD has no cure. The same page calls quitting the single most effective intervention in preventing further damage to the lungs, says it slows progression, and says cough often improves compared with people who keep smoking. Health Canada attributes about 80% of COPD deaths to smoking. Read more in COPD stages and smoking and what smoker’s lungs look like.
When does lung cancer risk fall?
Slowly. Health Canada says 10 to 15 years after quitting, lung cancer risk is about half that of someone who continues to smoke, and that the earlier you quit the greater the long-term benefit. It estimates 72% of lung cancer cases in Canada are caused by smoking. Whether you may qualify for screening is covered by the lung screening eligibility checker, and the pack-year calculator helps with the numbers.
Why can the cough change in the first weeks?
Health Canada’s timeline lists the cough as decreasing, and we found no official statement about a temporary increase. If your cough changes, gets worse or lasts, see when to see a doctor about a smoker’s cough.
Health information is general and educational. It does not replace advice from a doctor, pharmacist or nurse. Read the full disclaimer.
Frequently asked questions
How long does it take for lungs to heal after quitting smoking?
Health Canada says the airways relax between 2 weeks and 3 months after quitting, and you cough less between 1 and 9 months. Its page gives no date by which lungs are fully healed.
Can lungs fully recover from smoking?
Not always. Health Canada describes emphysema as gradual and irreversible damage of lung tissue, and says COPD has no cure. It also calls quitting the single most effective way to prevent further lung damage.
Does lung cancer risk drop after quitting?
Yes. Health Canada says that 10 to 15 years after quitting, lung cancer risk is about half that of someone who keeps smoking.
Sources
- Quit smoking: decide to quit — Health Canada. Accessed October 27, 2026.
- Tobacco and chronic obstructive pulmonary disease — Health Canada. Accessed October 27, 2026.
- Tobacco and lung cancer — Health Canada. Accessed October 27, 2026.