Factor V Leiden

What is Factor V Leiden?

Factor V Leiden is the name of the genetic variation that increases the tendency for the body to form large blood clots (also known as thrombophilia). Factor V Leiden thrombophilia is a blood clotting disease that runs in the family, meaning people are at high risk for developing this disease if someone else in their family has it. While factor V Leiden increases the risk for blood clots, only a small percentage of the people who have it develop abnormal clotting. There are also other factors that create a greater risk of developing blood clots.

Symptoms and Complications

Blood clots can block normal blood flow in veins and arteries. Sometimes clots can break free and travel to the legs and lungs. If you have factor V Leiden thrombophilia, these are some conditions and symptoms to look out for:

A deep vein thrombosis (DVT) is a clot that blocks blood flow in the legs. Symptoms may include:

  • Pain, throbbing, or a persistent cramp-like feeling
  • Feeling of warmth on the leg
  • Redness or discoloration
  • Swelling in the affected leg (it is rare that both legs are swollen)

A pulmonary embolism (PE) is a clot that travels and blocks blood flow in the lungs. Symptoms may include:

  • Sudden shortness of breath
  • Sharp chest pain when inhaling or breathing in
  • Coughing up blood or blood-tinged saliva
  • Fast heartbeat

If you suspect you have a DVT or a PE, call 911 right away.


Factor V Leiden can be confirmed by a blood test and by genetic testing. A health care provider may test you for factor V Leiden if you have had abnormal clotting or have a strong family history of clotting problems.


Clinicians or providers may prescribe blood-thinners to help prevent blood clots for people who are considered high risk. However, this type of medication may not be needed if people with factor V Leiden have never experienced abnormal blood clots.

Your provider might suggest other ways to prevent blood clots:

  • Leg wraps that inflate and deflate to keep blood moving in your legs
  • Compression stockings
  • Going for regular walks

Things you can do at home to prevent blood clots. Make sure to consult with your provider to see if the following precautions are right for you.

  • Keep legs moving and change positions often: When our bodies remain still, our muscles don’t contract. Contracting muscles help blood move throughout our body. This is why regular exercise and walking are important in preventing blood clots and improving circulation.
  • Drink water: Being dehydrated causes our blood vessels to narrow and the blood to thicken. Staying hydrated helps to improve our circulation. If your doctor or provider has advised you to be on a fluid restriction, it’s important to stay within your recommended fluid intake.
  • Raise your legs: From time to time, when you are laying down, prop your legs on a pillow (or two) to elevate them above the heart. Stay in this position for about 15-20 minutes at a time.
  • Wear compression stockings: If you’re at high risk for clots, compression stockings help promote better circulation. These stockings typically require a prescription so make sure to discuss it with your provider.
  • Lifestyle and diet changes: Smoking causes your blood vessels to narrow and too much salt in your diet can dehydrate you. A healthy, balanced diet and limiting salty and fried foods can decrease your risk for clots. Limiting certain habits such as smoking and drinking alcohol can also improve your overall health.

For more information on blood clotting, visit https://vascularcures.org/2022/03/24/what-are-blood-clots/. If you have been diagnosed with factor V Leiden and want to help others learn more about your experience, visit PatientsLikeMe.

For more in-depth information and resources regarding this rare disease, visit:

Risk Factors

  • Family history
  • Age
  • Excess weight /li>
  • Estrogens (in birth control pills or hormone replacement therapy)
  • Smoking
  • Pregnancy

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