Smoking tobacco products such as cigarettes and cigars markedly increases your risk of contracting one or more life-threatening illnesses. One of every five deaths that occur in the United States annually is the result of health problems induced by cigarette smoking, according to the Centers for Disease Control and Prevention. Upon quitting, a smoker's health may begin to improve within hours.
Tobacco smoke contains no less than 69 carcinogens, according to the National Cancer Institute. Carcinogens are substances that potentially can cause cancer by directly or indirectly interfering with the genetic information found inside cells. Among the carcinogens present in tobacco smoke are ammonia, vinyl chloride, benzene, carbon monoxide and cadmium. Smoking can lead to cancer of the lungs, mouth, larynx, esophagus, stomach and pancreas and has been linked to acute myeloid leukemia. Approximately 30 percent of all cancer cases in the United States are related to smoking, according to the American Cancer Society.
Smoking increases your blood pressure and depletes the body's beneficial cholesterol, known as HDL, whose functions include preventing harmful cholesterol -- LDL -- from building up inside arteries. As a result, smokers are more prone to arteriosclerosis, an accumulation of fatty substances collectively termed plaque. Arteriosclerosis is a major factor in the development of heart disease. Smoking also makes blood more clot-prone, which, combined with increased LDL levels, has the potential to cut off blood flow to the brain and cause a stroke. In addition, smoking increases your risk of an abdominal aortic aneurysm, a dangerous swelling of the portion of the body's main aorta found in the abdomen.
Smoking stimulates the production of mucus in the lungs while hampering and destroying the hair-like structures know as cilia that clean out mucus and toxins. Excess mucus often is manifested as a chronic cough and make lungs more susceptible to infections. Smokers may therefore experience more colds with more severe symptoms. Moreover, smoking increases your likelihood of dying from chronic obstructive pulmonary disease, which can involve emphysema and chronic bronchitis. The former refers to the destruction of the air sacs that allow lungs to expand; the latter is a condition in which the passageways inside lungs swell. Both emphysema and chronic bronchitis make breathing difficult.
The deterioration of your cardiovascular and respiratory systems due to smoking limits your ability to exercise and participate in sports, according to the American Heart Association. Smokers are more likely to have a fast heart rate, suffer from poor circulation and experience shortness of breath due in part to the presence of carbon monoxide, which displaces oxygen in the blood. All organs are deprived of oxygen as a result, including muscles, which under such conditions cannot withstand the demands of physical activity.
Women who smoke while pregnant increase their risk of giving birth prematurely. Low birth weight also has been linked to smoking. Moreover, women who smoke generally have lower bone density when they reach menopause than nonsmoking women, according to the CDC, and consequently are more prone to hip fractures.