Factor V Leiden Thrombophilia: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Factor V Leiden Thrombophilia?
A hematologist, a doctor specializing in blood conditions, treats this condition. Most people start with a primary care doctor, who can order tests and refer them to a hematologist when needed. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
Factor V Leiden thrombophilia makes blood more likely to clot than it should. It comes from a change in a gene called Factor V. Many carriers never develop a clot, but their risk is higher than average.
Symptoms
Most people have no symptoms. A clot in a deep vein is called deep vein thrombosis and can cause swelling, pain, warmth, or redness in one leg. If a piece travels to the lungs, it is a pulmonary embolism, causing sudden shortness of breath, chest pain, or coughing up blood.
Causes and who gets it
Factor V Leiden is inherited. It is the most common inherited cause of abnormal clotting. Most carriers never develop a clot, but risk rises with pregnancy, birth control pills or hormone therapy, surgery, long periods of sitting, obesity, or smoking.
How doctors diagnose it
Doctors often find Factor V Leiden after a clot. The main test is a blood test that looks for the gene change. Testing is not routine; doctors usually suggest it only for people with a personal or family history of clots.
Treatment
Many people never need treatment. When a clot happens, doctors usually prescribe blood thinners, such as warfarin, rivaroxaban, and apixaban. How long treatment lasts depends on where the clot was and the person's overall risk.
When to see a doctor
Call a doctor for swelling, pain, or warmth in one leg. Get emergency help for sudden shortness of breath, chest pain, or coughing up blood, which can signal a clot in the lungs.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee, while a concierge doctor charges more and often works alongside insurance. Either can be a good first stop, and longer visits help when discussing family history and genetic testing. They can order blood tests, prescribe blood thinners for a simple clot, and refer serious or complicated cases to a hematologist.
Common questions
Can Factor V Leiden be cured?
No. It is a gene change you are born with, and it cannot be removed. The good news is that many carriers never develop a clot. Clots that do happen can usually be treated.
Should my family members get tested?
It depends. If you have the gene change and have had a clot, or if clots run in your family, relatives may want to ask a doctor about testing. A doctor can help them decide if testing would change anything for them.
Can I still take birth control pills if I have Factor V Leiden?
Estrogen-containing birth control pills raise clot risk. That risk is higher in people with this gene change. Many doctors recommend other types of birth control instead. Talk with your doctor about the safest options for you.
Do I need to take a blood thinner for the rest of my life?
Usually not after a first clot. Doctors often prescribe blood thinners for a limited time and then reassess. Lifelong treatment is more likely for people who have clots more than once or who have other high-risk factors.
Sources
- MedlinePlus Genetics - Factor V Leiden thrombophilia
- National Organization for Rare Disorders (NORD) - Thrombophilia Awareness Project - National Organization for Rare Disorders
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
