Description

Understanding Your Risk for Abnormal Blood Clots

What is Factor V Leiden?

Factor V Leiden is a genetic mutation of a blood clotting factor (Factor V) that increases your risk of developing abnormal blood clots, especially in the legs (deep vein thrombosis – DVT) or lungs (pulmonary embolism – PE). Most individuals with this mutation never develop a clot, but for those who do, the consequences can be serious.

Why You Might Need This Test

This test may be recommended if you have:

  • A personal or family history of abnormal blood clots
  • A history of blood clots at a young age (before age 50)
  • Recurrent pregnancy loss or complications
  • A clot with no obvious cause (unprovoked DVT or PE)
  • A close relative with a known Factor V Leiden mutation

Symptoms That May Indicate a Clot

Deep Vein Thrombosis (DVT):

  • Swelling in one leg (or arm)
  • Redness or discoloration
  • Pain or tenderness, especially in the calf
  • Warmth over the affected area

Pulmonary Embolism (PE):

  • Sudden shortness of breath
  • Sharp chest pain, especially with breathing
  • Coughing up blood
  • Rapid or irregular heartbeat

If you experience these symptoms, seek medical attention immediately.

About the Test

The Factor V Leiden test is a genetic blood test that checks for the presence of the mutation in one or both copies of the gene. It helps determine if you have an increased risk for clotting events, allowing for preventive measures or changes in care.

Fasting not required.