What Are the Risks of Smoking?
The chemicals in tobacco smoke harm your heart and blood vessels in many ways. For example, they:
• Thicken your blood and make it harder for your blood to carry oxygen.
• Increase your blood pressure and heart rate, which makes your heart work harder than normal.
• Lower your HDL cholesterol (sometimes called "good" cholesterol) and raise your LDL cholesterol (sometimes called "bad" cholesterol). Smoking also increases your triglyceride level. Triglycerides are a type of fat found in the blood.
• Disturb normal heart rhythms.
• Damage blood vessel walls, making them stiff and less elastic. This narrows the blood vessels and adds to the damage caused by unhealthy cholesterol levels.
• Contribute to inflammation, which may trigger plaque buildup.
Smoking and Heart Disease Risk
Smoking is a major risk factor for coronary heart disease (CHD). CHD is a condition in which plaque builds up inside the coronary arteries. These arteries supply your heart muscle with oxygen-rich blood.
Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. When plaque builds up in the arteries, the condition is called atherosclerosis.
Plaque narrows the arteries and reduces blood flow to your heart muscle. The build up of plaque also makes it more likely that blood clots will form in your arteries. Blood clots can partly or completely block blood flow.
Over time, smoking contributes to atherosclerosis and significantly increases your risk of having and dying from heart disease, heart failure, or a heart attack.
Compared with people who don't smoke, people who smoke can be up to two to three times more likely to have heart disease and twice as likely to have a heart attack. The risk of having or dying from a heart attack is even higher among people who smoke and already have heart disease.
For some people, such as women who use oral contraceptives and people who have diabetes, smoking poses an even greater risk to the heart and blood vessels.
Smoking by itself is a major risk factor for heart disease. When combined with other risk factors—such as unhealthy blood cholesterol levels, high blood pressure, and overweight or obesity—smoking further raises the risk of heart disease.
Any amount of smoking, even light or occasional smoking, harms your body. Research suggests that smoking can even cancel out the benefits of other efforts to reduce heart disease risk, such as taking aspirin or medicines to lower cholesterol.
Smoking and Peripheral Arterial Disease Risk
Peripheral arterial disease (P.A.D.) is a disease in which plaque builds up in the arteries that carry blood to your head, organs, and limbs. P.A.D. usually affects the arteries that carry blood to your legs.
Blocked blood flow in the leg arteries can cause cramping, pain, weakness, and/or numbness in your hips, thighs, and calf muscles. Blocked blood flow also can raise your risk of getting an infection in the affected limb. It may be hard for your body to fight the infection.
If severe enough, blocked blood flow can cause gangrene (tissue death). In very serious cases, this can lead to leg amputation.
If you have P.A.D., your risk of heart disease and heart attack is six to seven times greater than the risk for people who don’t have P.A.D. Smoking is a major risk factor for P.A.D. Your risk of P.A.D. increases four times if you smoke or have a history of smoking.
Smoking even one or two cigarettes a day can interfere with P.A.D. treatments. People who smoke and people who have diabetes are at highest risk for P.A.D. complications, including gangrene in the leg from decreased blood flow.
What Are the Risks of Secondhand Smoke?
Secondhand smoke is the smoke that comes from the burning end of a cigarette, cigar, or pipe. Secondhand smoke also refers to smoke that’s breathed out by a person who is smoking.
Secondhand smoke contains many of the same harmful chemicals that people inhale when they smoke. It damages the heart and blood vessels in the same ways that active smoking does. Secondhand smoke greatly increases the risk of heart attack and death.
What Are the Risks of Cigar and Pipe Smoke?
Researchers know less about how cigar and pipe smoke affects the heart and blood vessels than they do about cigarette smoke. However, the smoke from cigars and pipes contains the same harmful chemicals as the smoke from cigarettes. Also, studies have shown that people who smoke cigars are at increased risk of heart disease.
What Are the Benefits of Quitting Smoking?
One of the most important things you can do to reduce your risk of coronary heart disease is to avoid tobacco smoke. Don’t ever start smoking. If you already smoke, quit. No matter how much or how long you've smoked, quitting will benefit you.
Also, avoid secondhand smoke. Don’t go to places where smoking is allowed, and ask friends and family members to not smoke in the house and car.
Quitting smoking has many benefits for your heart and blood vessels. For example:
• The risk of heart disease from smoking begins to decrease very soon after you quit. It continues to decrease even years after you quit. The risk is cut in half 1 year after quitting. If you have not developed heart disease within15 years of quitting, your risk of developing it is nearly the same as the risk in someone who has never smoked.
• Deaths from heart disease are reduced by one-third in people who quit smoking compared with people who continue smoking. Deaths from secondheart attacks are reduced by about the same amount.
• People who smoke and already have heart disease reduce their risk ofsudden cardiac death, second heart attack, and death from other chronic diseases by as much as half if they quit smoking.
• The risk of developing atherosclerosis and blood clots declines over time after you quit smoking.
Quitting smoking can lower your risk of heart disease as much as, or more than, common medicines used to lower heart disease risk, including aspirin, statins, beta-blockers, and ACE inhibitors.
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