Tomorrow, thousands of smokers across the United States will try to kick the habit for just one day as a part of the “Great American Smokeout.”

The American Cancer Society began the annual event 35 years ago as a national campaign to promote a smoke-free lifestyle. The hope is that smokers who go one day without smoking will eventually be able to quit for good.

And the ACS offers just a few good reasons smokers should consider stopping for good:

• 20 minutes after quitting: Your heart rate and blood pressure drop.

• 12 hours after quitting: The carbon monoxide level in your blood drops to normal.

• 2 weeks to 3 months after quitting: Your circulation improves and your lung function increases.

• 1 to 9 months after quitting: Coughing and shortness of breath decrease; cilia (tiny hair-like structures that move mucus out of the lungs) regain normal function in the lungs, increasing the ability to handle mucus, clean the lungs, and reduce the risk of infection.

• 1 year after quitting: The excess risk of coronary heart disease is half that of a smoker’s.

• 5 years after quitting: Your stroke risk is reduced to that of a non-smoker 5 to 15 years after quitting.

• 10 years after quitting: The lung cancer death rate is about half that of a person who continues smoking. The risk of cancer of the mouth, throat, esophagus, bladder, cervix, and pancreas decreases, too.

• 15 years after quitting: The risk of coronary heart disease is the same as a non-smoker’s.

Nicotine is highly addictive and quitting is hard. But tobacco use remains the single largest preventable cause of disease and premature death in the United States.

If you love a smoker, encourage him or her to quit for just one day – over and over again.