Antiphospholipid Syndrome: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Antiphospholipid Syndrome?
Antiphospholipid syndrome is usually treated by a rheumatologist, a doctor who treats autoimmune diseases. A hematologist, a doctor who treats blood disorders, may also help manage blood clots. 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 is antiphospholipid syndrome?
Antiphospholipid syndrome is an autoimmune disorder. Autoimmune means the immune system attacks the body's own tissues. In this condition, the immune system makes abnormal antibodies. Antibodies are proteins that normally fight germs. Here they attack proteins in the blood. This raises the chance of blood clots that can block blood vessels.
Clots can form in almost any blood vessel. If a clot forms in the brain, it can lead to a stroke. Women with the condition have a higher risk of problems during pregnancy. These problems include miscarriage, early delivery, and an underdeveloped placenta. The placenta is the organ that feeds the baby in the womb.
Symptoms
A clot or a pregnancy complication is often the first sign. Some people carry the antibodies but have no symptoms. Signs can include:
- Blood clots in the legs, arms, or lungs.
- Stroke or migraine headaches.
- Repeated miscarriages.
- Thrombocytopenia, a low amount of platelets, the cells involved in blood clotting.
- A purplish skin pattern called livedo reticularis.
- Skin ulcers, which are open sores.
Causes and who gets it
The exact cause is not known. Gene changes and other factors, such as an infection, may play a part. Triggers like infection, smoking, prolonged bed rest, pregnancy, or hormone therapy may cause a clot in someone who already carries the antibodies. It is often found in people with other autoimmune diseases such as lupus. Women get it more often than men.
How doctors diagnose it
Doctors diagnose it when a person has had a blood clot or repeated miscarriages. Blood tests for the antibodies must also be positive. Tests include the lupus anticoagulant, anticardiolipin antibodies, and antibodies to beta-2 glycoprotein I. A positive test must be confirmed after 12 weeks. A positive test without a clot or pregnancy loss does not mean you have the condition.
Treatment
Treatment aims to prevent new clots or keep existing clots from growing. You will need to take some form of blood-thinning medicine for a long time. Treatment often starts with heparin, which is given by injection. In most cases, warfarin, a blood thinner taken by mouth, is then started. Its level is checked often with blood tests. Women with the condition who become pregnant do not take warfarin; they receive heparin shots instead. If you also have lupus, your doctor may recommend hydroxychloroquine. To help prevent clots, avoid most birth control pills and hormone treatments for menopause. Currently, other types of blood thinning medicines are not recommended.
When to see a doctor
Contact a doctor right away if you notice symptoms of a blood clot, such as swelling or redness in a leg, or pain and pale skin color in an arm or leg. Call 911 for sudden shortness of breath, chest pain, sudden numbness or weakness, or trouble speaking. These can be signs of a blood clot or a stroke, which are emergencies.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Blood thinners need regular monitoring. A primary care doctor can schedule follow-up visits and lab work. They can also coordinate your rheumatologist or hematologist over time.
Common questions
Can antiphospholipid syndrome be cured?
It depends on how well treatment keeps clots under control. With treatment, the risk of new clots is lower. Most of the time, the outcome is good with proper treatment, which includes long-term blood thinning medicine. Some people have clots that are hard to control even with treatment.
Why are blood tests repeated after 12 weeks?
A positive test on its own does not mean you have the condition. The positive tests need to be confirmed after 12 weeks. A diagnosis needs a clot or pregnancy loss plus a test that stays positive.
Can I get pregnant if I have antiphospholipid syndrome?
Yes, but pregnancy needs close monitoring by a doctor who knows this condition well. You will not take warfarin during pregnancy; you will be given heparin shots instead.
What is catastrophic antiphospholipid syndrome?
It is a rare, severe form where clots suddenly develop in many arteries over a period of days. It can lead to stroke as well as clots in the kidney, liver, and other organs. It is life threatening, even with treatment. Treatment often combines blood thinners, high dose steroids, and plasma exchange. Plasma exchange filters the blood.
Sources
- MedlinePlus Genetics - Antiphospholipid syndrome
- MedlinePlus Medical Encyclopedia - Antiphospholipid syndrome - APS
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.
