Your risk of developing a blood clot in the deep veins of the legs (deep vein thrombosis, or DVT) depends on whether you have characteristics and conditions that increase your risk, called risk factors. Certain situations can also " trigger" a blood clot to form, especially in women who are already at risk.
See also: Symptoms of DVT
Risk Factors for Blood Clots in the Veins
The conditions below all make a woman more likely to develop blood clots, and you can minimize your risk by getting them under control with lifestyle changes and medication. Click any title to learn what it is, how to know if you have it, and how it affects your risk of DVT and pulmonary embolism.
- Overweight and obesity
- Inherited blood clotting problems
- Other heart conditions
- High levels of homocysteine, a protein component in the blood
- Hormone treatment (birth control pills or menopausal hormone replacement therapy)
You cannot change some of your risk factors for DVT. Even though you cannot change them, knowing you are at risk can motivate you to address the risk factors you can change. DVT risk factors that you have no control over include:
- Your age - your risk of blood clots in the veins doubles every 10 years after age 50
- Your family history – women who have a parent, sibling, or child who have had blood clots in the veins are more likely to develop them
- Your race – DVT is more common in certain races, especially African-Americans
- Cancer or chemotherapy can also increase your blood clot risk
Recognizing which conditions are putting you at risk is the first step towards preventing DVT. See Preventing DVT: The Basics for tips on working with your doctor to get your risk factors under control and reduce your risk of developing blood clots in the veins.
While the above factors make you more likely to develop DVT, often a "trigger" event causes the blood clot to form. Common triggers include:
- Major surgery
- Trauma (especially fractures of the pelvis, hip, or leg)
- Pregnancy and the first few months after the baby is born
- An extended period of immobility, for example:
- During a hospital stay
- After surgery, injury, or illness
- In a nursing home
- During long travel - travel of 4 hours or more (flying, driving, or on bus or train) doubles your risk of blood clots for weeks after the trip; longer travel increases risk even more
See Preventing DVT: The Basics for tips on working with your healthcare team to minimize your DVT risk in these situations.