Tobacco comes from a plant and contains the stimulant drug, nicotine. Nicotine increases pulse rate and blood pressure. The effects can usually be felt immediately, and can last up to 30 minutes from one cigarette. Regular users often report that smoking reduces their anxiety and helps them relax.
Some smokers say nicotine reduces their appetite, so they eat less.
Tobacco is highly addictive. Regular use can result in physical dependency with long-lasting withdrawal symptoms. Depression, irritability, restlessness and anxiety are some of the symptoms experienced by smokers who haven't had a cigarette in a while. These symptoms produce a strong craving for another cigarette. Coughing, as well as other chest and breathing problems afflict some smokers.