Stroke And Blood Clots - Hormone Therapy And Disease: Menopause

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Stroke and blood clots

Hormones appear to increase the blood's tendency to clot, an observation that ties in with the slightly higher risk of stroke and blood clots seen in women who take hormones. Numerous studies have documented a slight increase in ischemic stroke (the type caused by a blood clot that blocks blood flow to the brain) among women who take hormones. (The other, less common type of stroke, known as a bleeding or hemorrhagic stroke, doesn't appear to be more common among hormone users.) These observations were upheld by the WHI findings: Both types of therapy (estrogen alone and combined hormone therapy) boosted the risk of stroke by about 40%. That is, an additional 7 women in 10,000 had a stroke.

Blood clots can also lodge in the deep veins of the legs (deep-vein thrombosis) and the lungs (pulmonary embolism). These dangerous conditions are also slightly higher among hormone users, as documented in earlier studies and the WHI results. Risk of clotting problems doubled for women in the WHI who took combined hormone therapy but increased by less than half for estrogen-only users.

Last updated:	August 13, 2007