Nicotine has a half-life of about two hours and can stay in the blood for about one to three days. Cotinine, a byproduct of nicotine, has a half-life of 18 hours and can last for several days.

From improvements to your skin to a lower risk of heart disease happens to your body in the hours, days, weeks and months after you give up cigarettes.

New research dismantles the long-held belief that smoking less means less harm. Scientists now say the body suffers significant cardiovascular damage from even low levels of smoking. Researchers from ...

Researchers say that smoking as few as two cigarettes a day can significantly increase a person’s risk of heart disease. Experts say there is no safe level of smoking, and the best preventive strategy ...

Nicotine quickly enters your bloodstream. Your liver then breaks down nicotine into several byproducts, primarily cotinine. Depending on what you're testing, such as a blood, urine, saliva, or hair ...

Share on Pinterest Even occasional smoking can significantly raise heart disease risk. Mal de Ojo Studio/Stocksy Researchers say that smoking as few as two cigarettes a day can significantly increase ...