Hormonal Birth Control and Blood Clot Risk – Consumer Health Info

Hormonal Birth Control & Blood Clot FAQs

How Common Are Blood Clots?

Blood clots are generally rare, but they can occur even in otherwise healthy people, including those who are not taking hormonal birth control. Out of every 10,000 women who are neither pregnant nor using hormonal birth control between 1 and 5 will experience a blood clot every year. Women using hormonal birth control with the combined hormonal contraceptive (CHC) feature have a slightly higher risk: between 3 and 9 in every 10,000 CHC users experience a blood clot in a given year.

What Types of Blood Clots Are There?

"Venous blood clots" or "venous thromboembolisms" (VTEs) are a mass of thickened blood inside a vein. Many people are familiar with deep vein thrombosis (DVT) and pulmonary embolism (PE), which are types of VTE. VTEs can travel through the bloodstream, damaging vital organs and even resulting in death. VTEs are the third-most common type of cardiovascular illness in the U.S. and cause 300,000 deaths annually.

Who's at Risk of Getting Blood Clots?

The highest risk of blood clots among reproductive-aged women occurs during pregnancy and in the postpartum period, when estrogen levels increase. Among pregnant women, between 5 and 20 in every 10,000 pregnant women will experience a blood clot in a year; 40 to 65 in every 10,000 postpartum women experience a blood clot in a year.

What Are Combined Hormonal Contraceptives (CHCs)?

Hormonal birth control methods that contain the hormones estrogen and progestin are called combined hormonal contraceptives (CHCs). CHC products include birth control pills, patches, and vaginal rings. While all CHCs carry some risk of blood clots, the risk can differ from product to product.

What Are the Signs and Symptoms?

Some people experiencing a blood clot have no signs or symptoms at all. When symptoms do occur, depending on where the blood clot is located in the body, people may experience some or all of the following:

  • swelling
  • pain
  • tenderness
  • redness of the skin
  • difficulty breathing
  • faster than normal or irregular heartbeat
  • chest pain or discomfort
  • anxiety
  • coughing up blood
  • very low blood pressure, light-headedness, or fainting

People experiencing any of these symptoms should seek medical care immediately.

Additional Information:

So, although hormonal birth control with the CHC feature increases the risk of blood clots, the risk is only slightly higher than the risk for women who don't use CHCs, and is significantly lower than the risk faced by pregnant women. Some personal characteristics and medical conditions increase the risk of blood clots, including (but not limited to):

  • obesity
  • genetic clotting disorders
  • smoking
  • being over age 60
  • prolonged inactivity (such as during long car or airplane rides)
  • surgery
  • cancer

Individuals with characteristics that increase their risk of blood clots should discuss the risks of using CHCs with their health care provider and/or pharmacist.

Resources

References

This fact sheet is meant to provide current and potential contraceptive users with information to help weigh the risks and benefits of using hormonal contraception. Readers are encouraged to consult their health care providers and/or pharmacists for a more detailed discussion of the risks of using combined hormonal contraception.