Quitting smoking causes day-by-day changes to your body.

Stopping smoking produces measurable changes within hours and days, such as a return toward normal pulse and improving oxygen levels, and it also lowers risks of heart disease and some cancers over years.

Many people choose January to try quitting smoking, and health organizations note benefits start soon after stopping. Smoking is linked to higher risks of stroke, lung disease, heart disease and multiple cancers, and official guidance says quitting improves health at any age. The body begins to remove some harmful chemicals quickly, and symptoms of withdrawal and mood changes can appear in the first days. Long-term reductions in disease risk are reported to develop over years. Reported changes: - Within 24 hours: pulse rate moves toward normal and oxygen levels begin to recover as carbon monoxide levels fall. - After two to three days: carbon monoxide is reported to be cleared and sense of taste and smell can improve while the lungs start clearing mucus. - Weeks to months: circulation and breathing are reported to improve, with coughing and breathlessness often easing and lung function showing measurable gains by about three months. - Years: reported reductions include a halving of some heart disease risks by about one year and substantially lower risk of death from lung cancer by ten years compared with continuing smokers. Summary: Quitting smoking leads to early, measurable changes in the body and to reduced long-term health risks. Undetermined at this time.