Smoking is one of the three classic risk factors for cardiovascular disease, smoking can cause atherosclerosis, which in turn significantly increases the morbidity and mortality of cardiovascular disease, in addition to smoking is also a risk factor for other chronic diseases such as malignancy and chronic obstructive pulmonary disease, smoking is a common trigger for the worsening of asthma and attacks, smoking is associated with at least 40 of the diseases and 20 types of cancer.