Although most strokes occur in people older than 50, about 1 in 5,000 women ages 15 to 49 suffers a stroke each year, according to the National Institute of Neurological Disorders and Stroke (NINDS).
A stroke occurs when brain cells die because the brain is deprived of oxygen. The most common cause of stroke is a blockage in an artery, a blood vessel that brings oxygen-rich blood to the brain. This type of stroke is called an ischemic stroke. The blockage is nearly always because of a blood clot that has formed in the artery and becomes so big that it stops or greatly decreases the amount of blood that can flow past it. The blockage can also be caused by a dislodged fragment of a clot from elsewhere in the body that has become wedged in an artery too narrow for it pass through.
Another type of stroke occurs when a tear in the wall of an artery in the brain allows blood to flow out of the artery. The blood leakage deprives the brain of oxygen. This type of stroke is called a hemorrhagic stroke.
How a stroke affects a person depends on where in the brain it has occurred and how many brain cells have died.
In younger women, the risk factors for stroke are migraine, autoimmune disorders, obesity, high blood pressure (hypertension), type 2 diabetes, and cardiovascular disease. Some research has shown that women who are obese or who have gained more than 44 pounds since they were 18 years old are about 2-1/2 times more likely to have an ischemic stroke than lean women who have not gained a lot of weight.
Smoking or using oral contraceptives also increases the risk for stroke. The stroke risk is increased even for women who use low-estrogen contraceptives. Women who smoke, are older than 35, and use oral contraceptives are at higher risk.
Healthy women ages 45 to 64 can cut their risk for ischemic stroke by exercising regularly, eating a healthy diet, drinking only moderate amounts of alcohol, not smoking, and controlling high blood pressure.
In general, African-American women are up to 3 times more likely that have a stroke than white women. For both African-American and white women ages 15 to 49, however, having a particular gene boosts the risk for ischemic stroke. The gene, phosphodiesterase 4D, encourages both the buildup of plaque in arteries and the formation of blood clots. It also raises the risk for hemorrhagic stroke. If you smoke and have a certain variation of this gene, you are at especially high risk for stroke, the NINDS says.
Pregnancy can slightly increase the risk for ischemic stroke. It is more of a risk for women with high blood pressure linked to pregnancy, a condition called preeclampsia or eclampsia, and for women undergoing cesarean delivery. A woman with preeclampsia during pregnancy is also at risk in the days just after delivery.
Younger women who use cocaine or methamphetamine are at greater risk for stroke.