Research has shown that cigarette smoke contains 56 toxic chemicals , including nicotine . People die. Of these , 1,75,000 are children. Children succumb to pneumonia and asthma due to secondhand smoke. In addition, secondhand smoke causes heart disease , lung cancer and other respiratory diseases. Studies have also shown that secondhand smoke has a more detrimental effect on women than men. About 61,000 women worldwide die each year as a result of secondhand smoke . A similar study, conducted in 2004, found that 40 % of those exposed to secondhand smoke were children , 33% were men and 33% were women. It also found that people in Europe and Asia suffer the most from secondhand smoke. [1] Major Respiratory Complications of Smoking Effects of Smoking on Cancer Production: Cigarette smoke contains carcinogenic mutants. They cause cancer of the human mouth , trachea , esophagus and lungs. Bronchitis: Smoking causes inflammation and coughing in the airways. This is called bronchitis. This causes the trachea to constrict slowly. Asthma causes shortness of breath. The lungs are largely inactive. Emphysema: Smoking narrows the airways and causes swelling in the lungs. This is called emphysema. This results in complex changes in the lungs. Coughing: Many people have a severe cough and cough due to smoking and mucus is seen coming out of the lungs. This is called whooping cough. Source: Wikipedia