Smoking and your heart

How does smoking affect the heart?

The chemicals in tobacco smoke can damage the lining of the coronary arteries, which supply the heart with oxygen-rich blood.

This damage leads to the build-up of fatty material in the walls of coronary arteries, which may block or narrow them. This is known as coronary heart disease.

In time your arteries may become so narrow that they cannot deliver enough oxygen-rich blood to your heart muscle. This can cause angina (a pain or discomfort in your chest).

Carbon monoxide

Carbon monoxide is a poisonous gas found in tobacco smoke. When you breathe it in it binds to your red blood cells, reducing their ability to carry oxygen around your body and depriving your heart and body tissues of oxygen. Having carbon monoxide in your blood greatly increases your risk of developing heart disease.

  • On average smokers die around 10 years earlier than non-smokers.
  • Smokers are at twice the risk of suffering a heart attack compared with people who have never smoked.
  • Stopping smoking after a heart attack reduces your risk of having a second. It also improves your chances of surviving another heart attack.
  • Stopping smoking before surgery, particularly heart surgery, reduces the risk of serious complications.

What happens after I stop smoking?

  • After 20 minutes your heart rate and blood pressure return to normal.
  • After eight-24 hours your lungs start to clear out mucus and other smoking debris.
  • After 72 hours your breathing is easier and you have more energy. Your sense of smell and taste improve.
  • After two-12 weeks your circulation improves and it becomes easier to walk and exercise.
  • After three-nine months your lung function increases by up to 10%.
  • After five years your risk of suffering a heart attack is cut by half.
  • After 10 years your risk of getting lung cancer is half that of a smoker. Your risk of a heart attack is the same as someone who has never smoked. 

Stopping smoking is one of the most important things you can do for your health. You are four times more likely to stop with the help of an NHS service (using stop smoking medication and support).

To be referred to your local stop smoking service or to speak to a specialist advisor please contact the Royal Free London stop smoking service on 020 7472 6393 or email

Alternatively you can call the National Stop Smoking Service on 0300 123 1044.

Download a PDF of this information.