SMOKING, BLOOD VESSELS, AND DEATH

Most people know that smoking is bad for your lungs and can cause cancer. However, fewer may be aware of the effects of smoking on the heart and the circulatory system—the arteries and veins that carry the blood throughout the body.

Cigarette smoking is the main preventable cause of premature death in the developed world. It accounts for nearly 440 000 deaths every year in the United States.When you smoke, toxic chemicals from tobacco enter your bloodstream. Some of these chemicals send signals to your heart to beat harder and faster. Smoking also causes blood vessels to constrict (become more narrow), forcing blood to travel through a smaller space. Both of these effects cause high blood pressure. Smoking also lowers high-density lipoprotein (good cholesterol) in your body and increases the likelihood of plaques (fatty buildups) collecting on the inside of blood vessels, a condition called atherosclerosis (hardening of the arteries). Smoking also increases the risk of thrombosis (blood clots blocking a blood vessel). Over time, these effects increase the risk of having a myocardial infarction (heart attack).

Smoking can also increase the risk of having a stroke (sudden blockage of blood circulation in the brain). A stroke is usually caused by a blood clot getting lodged in the blood vessels supplying the brain with blood and oxygen. When this happens, brain cells begin to die. This can cause permanent brain damage or even death. Women who smoke and use oral contraceptives (birth control pills) are at a much higher risk of developing heart disease or having a stroke than women taking oral contraceptives who do not smoke.