Can your lungs heal from smoking?

What heals after you quit, and what doesn't

Smoking harms your lungs in two different ways, and they recover very differently. The first kind of harm is irritation and clogging. Cleveland Clinic explains that tar and other chemicals in smoke paralyse the cilia (the hair-like cells that sweep germs and mucus out of your airways) and that the irritation causes inflammation and extra mucus. This kind of harm is largely reversible. The second kind is structural: smoke damages the walls of the tiny air sacs (alveoli). Once those walls break down, the result is emphysema, one form of COPD, and that damage is permanent.

Even when damage is permanent, quitting still changes what happens next. The CDC says quitting slows the progression of COPD and reduces the loss of lung function over time. You can't get destroyed air sacs back, but you can protect the ones you still have.

Lung recovery timeline after quitting smoking

How long does it take for your lungs to heal after you quit smoking? These are typical ranges from the NHS, Quit (Australia), the American Lung Association and the CDC. Your own pace depends on how much and how long you smoked, and on whether you already have a smoking-related lung condition. Quit makes the same point.

1. 48 hours: mucus starts to clear

   The NHS says that by 48 hours carbon monoxide has dropped to non-smoker levels, your lungs start clearing out mucus, and taste and smell improve. At 72 hours breathing can feel easier as your bronchial tubes relax. See what happens after 3 days.

2. Weeks 1–4: cilia wake up and you may cough more

   Cleveland Clinic says the cilia grow back and start working again fairly quickly, and that inflammation and mucus production calm down in the weeks after quitting. As the cilia start sweeping again, many people get a "quitter's cough" that can last for the first couple of months. That cough is part of the clean-up. Read more in cough after quitting smoking.

3. 2 weeks to 3 months: lung function starts to improve

   The American Lung Association says lung function begins to improve between 2 weeks and 3 months after quitting. Quit says that within three months you cough and wheeze less, and your lungs get better at clearing out mucus, tar and dust. The National Cancer Institute describes "substantial improvements in lung function" within several months.

4. 1–9 months: cough and breathlessness ease

   The American Lung Association and Cleveland Clinic both put the easing of coughing and shortness of breath at 1–9 months. The NHS says lung function can rise by up to 10% between 3 and 9 months. Quit adds that within six months you are less likely to be coughing up phlegm, and Cleveland Clinic notes that the risk of lung infections starts to fall as lung function improves.

5. 1 year: breathing easier for good

   Quit says that after a year your lungs are healthier and you'll be breathing more easily than if you had kept smoking. The CDC notes that quitting also reduces respiratory infections such as bronchitis and pneumonia.

6. Years 1–11+: COPD progression slows

   The Lung Health Study followed smokers with early airflow problems for 11 years. Each year, men who quit lost about 30 ml of lung function (FEV1) and women about 22 ml. People who kept smoking lost about 66 ml (men) and 54 ml (women). By year 11, 38% of continuing smokers had lung function below 60% of the expected value, compared with 10% of people who had stayed quit.

7. 10–15 years: lung cancer risk halves

   The NHS and the American Lung Association say the risk of dying from lung cancer is about half that of a smoker after 10 years. The CDC and Quit put the halving of added lung cancer risk at 10–15 years. Quit adds that this assumes the cancer was not already present when you quit.

Want to see where you are today? Enter your smoke-free days in the lung recovery timeline tool, or read the full quit smoking timeline for heart, circulation and other changes.

Can your lungs heal after 5, 10, 20 or 30+ years of smoking?

No study gives an exact recovery figure for each number of years smoked, so be wary of any page that does. Here is what the evidence does say. The NHS says the chance of developing COPD rises the more you smoke and the longer you've smoked. Quit says recovery depends on how much and how long you smoked. And the National Cancer Institute says that although it is never too late to benefit, the benefit is greatest for people who quit younger. How much you smoked per day matters as well as how many years, which is why doctors use pack-years (one pack a day for one year is one pack-year).

If you're over 40 or 50, see our guides to the health benefits of quitting and how to quit smoking.

How to help your lungs recover

• •Stop completely. Cutting down still exposes your airways to smoke. The CDC says that if you keep smoking, COPD damage happens faster than if you stop.
• •Move every day. Quit says exercise helps your lungs clear. Walking is enough to start.
• •Let the cough do its job. A new, looser cough in the first couple of months is usually the cilia clearing mucus (Cleveland Clinic).
• •Get a baseline breathing test if you smoked for many years, get breathless easily, or have a long-standing cough. The earlier COPD is found, the more you can protect. If you have asthma, see quitting smoking with asthma.
• •Use free quit support. Your local NHS Stop Smoking Service (UK), Quitline 13 7848 (Australia), or 1-800-QUIT-NOW (US).