According to the National Heart, Lung, and Blood Institute, the formation of blood clots in the legs is a rare but serious complication that has frequently been associated with the use of birth control pills. Until recently, low-dose estrogen replacement therapy in post-menopausal women was believed to be free of this rare complication. Now, new studies show that even a low-dose estrogen therapy can significantly increase the risk of blood clots in the legs.
The good news for most women is that the actual risk of hormone-induced DVT remains small, perhaps being outweighed by the potential benefits of estrogen replacement for treating the vasomotor symptoms (hot flashes, night sweats) of menopause, as well as the other benefits of estrogen such as reducing the risk of osteoporosis and heart disease . However, the use of estrogen as a preventive measure against heart disease is clearly one that is still under study and highly debatable; the American Heart Association recently came out against the use of estrogen if the primary purpose is to prevent heart disease.
What Is Deep Vein Thrombosis?
Deep vein thrombosis is the formation of a blood clot (thrombus) deep within a vein. These blood clots occur most often in the calf or thigh and can partially or completely block the flow of blood in the affected vein.
Hormonal factors are not the only cause of blood clots in the legs. Other causes of DVT include:
- Poor
circulation caused by conditions such as a recent heart
attack or stroke, or other forms of heart disease.
- Varicose
veins.
- Long-term
inactivity.
- Extended
bed rest.
- DVT
can also occur during a long flight when passengers often
have little room to move their legs. This condition is
known as 'Economy Class Syndrome.' Certain people are
considered most at risk for in-flight DVT; these people
include pregnant women, people who are overweight, those
whose feet do not touch the floor, older passengers,
smokers, and people with coronary artery disease or
certain blood conditions. To prevent DVT from occuring
during or after an airplane flight, it's recommended that
passengers try to get up and walk up and down the aisle
at least once an hour.
- An
injury to a vein can bring on an occurrence of deep vein
thrombosis. A vein can be injured in several ways
including a blow to the leg, surgery, or radiation
treatments for cancer. Such an injury can cause a
narrowing or blockage in a vein where it then gathers
blood and clots.
- Pregnancy
increases the risk of DVT developing because of the
body's natural tendency to prevent excessive bleeding
during childbirth.
- Other potential causes include severe infection, liver disease, and some forms of cancer.
People who are elderly and those who are obese experience the highest rates of deep vein thrombosis; however, this in no way means that healthy, young individuals have nothing to worry about. Certain people, born without important blood thinning properties, are always at an increased risk for developing blood clots.
