Why does estrogen cause blood clots

It should be noted that estrogen alone does not cause blood clots, but it does increase the risk of blood clots forming by several times. Birth control pills which contain estrogen are the number one method of birth control in the United States, and these pills increase the chances of a blood clot by around three times. Because many birth control pills contain estrogen and progestin, women aged 18-45 are exposed to increased estrogen levels in their blood. Not only does estrogren increase the risk of clotting, but it is also assumed to be the cause of increased risk of blood clots during a pregnancy.

While estrogen does increase the chance of blood clots forming, the absolute risk of a clot forming in women who take birth control is still relatively small. However, women who have a history of blood clotting, or thrombophilia, should avoid birth control, as the estrogen from these pills can make the risk of blood clots that much more substantial. In addition, women who choose to use the patch over the pill could be at higher risk for blood clots, since more estrogen is absorbed through the skin, than with women who ingest the pill. As for women who use birth control rings, there is little information concerning the risk of blood clots caused by them, but just as with the patches and pills which contain estrogen, it is assumed that the birth control ring carries the same risks.

Aside from being used to prevent pregnancy, estrogen is also used to treat postmenopausal symptoms. Many post menopausal hormone therapy consists of a pill which is very similar to the birth control pill. This pill contains estrogen and progestin, which is a synthetic progesterone. Since these pills do contain estrogen, women who ingest them for postmenopausal hormone therapy have an increased risk of developing a blood clot. However, the risk still remains small, as it is reported that only one in 300 women per year who take postmenopausal hormone therapy pills actively develop any type of blood clot. This is of course, not true of women who have a history of blood clots, or women who have been diaganosed with thromophilia.
Aside from the risk factors associated with estrogen and its treatments, postmenopausal hormone therapy also increases the risk of breast cancer, stroke, deep vein thrombosis and pulmonary embolism. It is unclear whether or not these symptoms are linked to the estrogen and progestin contained in the pills. Many women seek postmenopausal hormone therapy in an attempt to manage their menopausal symptoms, such as hot flashes, sleeplessness, vaginal dryness, and bone loss, but all of these symptoms can be addressed without the use of estrogen, which significantly lowers a woman’s chances to develop a blood clot.

For women who need postmenopausal hormone therapy, the risks of blood clots should be made clear and understandable, as blood clots developed in older women can be fatal, as the clots pool in the lungs and cause significant health problems.