Cancer
In addition to the addictive nicotine, cigarettes contain over 7,000 chemicals. So far, around 70 of these chemicals are known to cause cancer. Lung cancer is the most common kind of cancer to develop from smoking, but smoking can also lead to cancer in the mouth, throat, nose, stomach, colon, and many other parts of the body.
Respiratory System
In addition to lung cancer, smoking can cause many other problems for your respiratory system. In a very short time, smoking can lead to frequent coughing, colds, wheezing, and asthma. It can also lead to more serious conditions such as emphysema, chronic obstructive pulmonary disease, and chronic bronchitis. In addition, smoking greatly increases your risk for potentially fatal diseases such as pneumonia and tuberculosis.