Why do hormones used in birth control lead to blood clots?
Many studies show that there is a slightly increased risk of developing blood clots while taking hormones for birth control. This is because oestrogen helps make the blood thicken. Why do blood clots kill? Many women will develop small blood clots, usually in the legs, which break up and dissolve of their own accord safely. In a few rare cases, the clots travel to the brain, where they can cause stroke and death. The World Health organisation has published a strict set of guidelines for who should be prescribed hormones. Who should not use the patch? • Women who smoke, especially those over 35. • Women with a previous or current blood clot, either in the leg or a lung. • Some women with high blood pressure. • Women with markedly abnormal function of the liver. • Some women with diabetes. • Women who are immobile, such as after major surgery. • Women who have just given birth. • Women with a history of migraines with auras. Should women worry? “The risk from either the patch or the Pill
