Dr. Clyde Yancy explains the health risks of smoking

Smoking is the most important preventable cause of premature death in the United States. Smokers have a higher risk of developing many chronic disorders, including atherosclerosis — the buildup of fatty substances in the arteries — which can lead to coronary heart disease, heart attack (myocardial infarction) and stroke. Controlling or reversing atherosclerosis is an important part of preventing future heart attack or stroke.

You can modify or control six major independent risk factors for coronary heart disease:

• Cigarette and tobacco smoke
• High blood cholesterol
• High blood pressure
• Physical inactivity
• Overweight or obesity
• Diabetes

Smoking by itself increases the risk of coronary heart disease. When it acts with the other factors, it greatly increases your risk from those factors, too. Smoking decreases your tolerance for physical activity and increases the tendency for blood to clot. It decreases HDL (good) cholesterol. Your risks increase greatly if you smoke and have a family history of heart disease. Smoking also creates a higher risk for peripheral artery disease and aortic aneurysm. It increases the risk of recurrent coronary heart disease after bypass surgery, too.

Smoking is also an important risk factor for stroke. Inhaling cigarette smoke produces several effects that damage the cerebrovascular system. Women who take oral contraceptives and smoke increase their risk of stroke many times.

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Cigars and pipes aren’t a "safer" alternative to cigarettes. People who smoke cigars or pipes seem to have a higher risk of death from coronary heart disease (and possibly stroke), even though their risk isn't as great as that of cigarette smokers.

It's also important to avoid other people's smoke. The link between secondhand smoke (also called environmental tobacco smoke) and disease is well known, and the connection to cardiovascular-related disability and death is also clear. Each year about 38,000 people die from heart and blood vessel disease caused by other people's smoke. Nonsmokers who are exposed to secondhand smoke at home or at work increase their risk of developing heart disease by 25–30 percent.

If you already have heart disease, you may think, "What good will it do me to quit smoking now?" But don’t be discouraged. Heart disease can be prevented and controlled, but you must follow your treatment plan — and quitting smoking is a big part.

This content is reviewed regularly. Last updated 09/02/09.