Smoking shortens life. It can cause atherosclerosis, heart disease, heart attacks and cancer. It doesn't only damage the coronary arteries of the heart, but it also damages other arteries in the body (such as the brain, kidneys and genitals) with unpredictable consequences. What is more, smoking indoors produces high concentrations of certain harmful substances that can cause negative symptoms in non-smokers. Parents who smoke can harm the health of their children.