Can secondhand smoke increase your risk of having a heart attack?

Answers from Richard D. Hurt, M.D.

Secondhand smoke exposure is a risk factor for having a heart attack. Breathing secondhand smoke can cause the cells in your blood that are responsible for clotting (platelets) to become stickier, making your blood more likely to clot. This can cause a clot to form that may block an artery, causing a heart attack or stroke.

Secondhand smoke also causes endothelial dysfunction, which makes the arteries unable to dilate. This condition is associated with most forms of cardiovascular disease, such as hypertension, coronary artery disease, chronic heart failure, peripheral artery disease, diabetes and chronic kidney (renal) failure.

Chemicals in secondhand smoke also irritate the lining of your arteries, causing them to swell (inflammation). This inflammation can narrow your arteries, increasing your risk of having a heart attack.

Many studies have proved that heart attack rates go down in areas after smoke-free laws are passed. If you smoke, the best way to reduce your heart attack risk is to quit. If you're regularly around smokers, encourage them to quit or smoke in outdoor areas that will reduce the amount of secondhand smoke others will breathe. This is especially important if you have had a previous heart attack or have been diagnosed with heart disease.


Richard D. Hurt, M.D.

Feb. 18, 2015