How long does it take for lung function to recover after quitting smoking?

Feb 26, 2025 Source: Cainiu Health

Dr. Ren Yi

Introduction

Within 8 hours after quitting smoking, the level of carbon monoxide in the blood begins to decrease, and oxygen levels start to rise. Within 24 hours, the risk of heart attack begins to decline. Between 2 weeks and 3 months, respiratory problems begin to improve, lung function gradually increases, and physical activity becomes easier. Within 1 to 2 years, symptoms of coughing and shortness of breath are significantly reduced.

　　If the smoking history is short and the individual's physical condition is relatively good, lung function typically recovers within 1-2 years after quitting smoking. If the smoking history is longer, it may take 5-10 years for lung function to recover.

　　Within 8 hours after quitting smoking, carbon monoxide levels in the blood begin to decrease while oxygen levels rise. Within 24 hours, the risk of heart attack starts to decline. Within 2 weeks to 3 months, respiratory problems begin to improve, lung function gradually increases, and breathing becomes easier during physical activity. By 1-2 years, symptoms such as coughing and shortness of breath significantly diminish, and the cilia in the lungs start to regrow, helping clear mucus and harmful substances from the airways.

　　Long-term heavy smokers may have already experienced significant lung damage, such as changes in alveolar structure and lung tissue fibrosis. The healing of such damage is a lengthy process, potentially requiring 5-10 years for lung function to approach the level of someone who has never smoked, although complete recovery to pre-smoking health levels is unlikely. Older individuals or those with generally poor health may experience slower recovery of lung function.

　　Smokers are advised to quit smoking as early as possible and maintain healthy lifestyle habits and regular medical check-ups to promote recovery of lung health.

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Is quitting smoking helpful for frequent shortness of breath?

Frequent shortness of breath can be effectively alleviated and respiratory function significantly improved by quitting smoking. Harmful substances in tobacco smoke damage the respiratory mucosa and exacerbate airway spasms and inflammation. Quitting smoking reduces irritation and slows the decline of lung function, making it a key measure to relieve wheezing. If shortness of breath is accompanied by chest pain, blood-tinged sputum, or worsening breathing difficulties, prompt medical attention is recommended.

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Will your lungs become clean after quitting smoking?

In general, the lungs gradually recover after quitting smoking, but whether they can become completely clean depends on the duration of smoking and the extent of damage. For those who smoked for a short period or have mild damage, lung health can improve significantly. However, long-term smoking that causes severe damage may result in irreversible changes. After quitting smoking, it is important to actively protect lung health by taking deep breaths in fresh air environments and engaging in regular moderate exercise to enhance lung function.

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Does bronchitis get passed on to the next generation?

In general, common acute bronchitis is not inherited by the next generation, but chronic bronchitis and certain special types of bronchitis may have a genetic predisposition. However, inheritance is not absolute and these conditions are more often influenced by interactions with environmental factors. Daily preventive measures are important, such as avoiding prolonged exposure to dust, smoke, and other irritants, quitting smoking, and staying away from secondhand smoke.