Because of their nicotine addiction, many smokers find it difficult to cease smoking despite their knowledge of ill health effects.The main health risks in tobacco pertain to diseases of the cardiovascular system, in particular myocardial infarction (heart attack), diseases of the respiratory tract such as Chronic Obstructive Pulmonary Disease (COPD), asthma,emphysema, and cancer, particularly lung cancer and cancers of the larynx and tongue.

 

A person's increased risk of contracting disease is directly proportional to the length of time that a person continues to smoke as well as the amount smoked. However, if someone stops smoking, then these chances gradually decrease as the damage to their body is repaired. A year after quitting, the risk of contracting heart disease is half that of a continuing smoker.

 

The health risks of smoking are not uniform across all smokers. Risks vary according to amount of tobacco smoked, with those who smoke more at greater risk. Light smoking is still a health risk.
Although pipe smoking also increases the risk of various cancers by 33%, the data regarding smoking to date focuses primarily on cigarette smoking, which increases mortality rates by 40% in those who smoke < 10 cigarettes a day, by 70% in those who smoke 10-19 a day, by 90% in those who smoke 20-39 a day, and by 120% in those smoking two packs a day or more.