Symptoms and causes

Symptoms

Signs and symptoms of antiphospholipid syndrome can include:

  • Blood clots in your legs (DVT). The clots can travel to your lungs (pulmonary embolism).
  • Repeated miscarriages or stillbirths. Other complications of pregnancy include premature delivery and high blood pressure during pregnancy (preeclampsia).
  • Stroke. A stroke can occur in a young person who has antiphospholipid syndrome but no known risk factors for cardiovascular diseases.
  • Transitory ischemic attack (TIA). Similar to a stroke, a TIA usually lasts only a few minutes and causes no permanent damage.
  • Rash. Some people develop a red rash with a lacy, net-like pattern (livedo reticularis).

Less common signs and symptoms include:

  • Neurological symptoms. Chronic headaches, including migraines; dementia and seizures are possible when a blood clot blocks blood flow to parts of your brain.
  • Cardiovascular disease. Antiphospholipid syndrome can damage heart valves.
  • Bleeding. Some people have a decrease in blood cells needed for clotting (platelets). If you have this condition (thrombocytopenia), you might have few or no symptoms.

    However, if your platelet count drops too low, you might have episodes of bleeding, particularly from your nose and gums. You can also bleed into your skin, which will appear as patches of small red spots (petechiae).

When to see a doctor

If you have another autoimmune condition, talk to your doctor about whether you should be tested for antiphospholipid antibodies.

Other reasons to contact your doctor include:

  • Pain, swelling, redness, or tenderness in your leg or arm. Seek emergency care if vein swelling and pain are severe or are accompanied by chest pain or shortness of breath.
  • Vaginal spotting or bleeding during pregnancy. This can be a sign of miscarriage or other pregnancy problems. However, many women who spot or bleed have a healthy pregnancy.

    If you've had pregnancy losses or unexplained severe complications of pregnancy, talk to your doctor about getting tested.

If you have antiphospholipid syndrome and you're thinking about getting pregnant, ask your doctor what treatments are available during your pregnancy.

When it's an emergency

Seek emergency care if you have signs and symptoms of:

  • Stroke. These include sudden numbness, weakness or paralysis of your face, arm or leg; difficulty speaking or understanding speech; visual disturbances; severe headache; and dizziness
  • Pulmonary embolism. These include sudden shortness of breath, chest pain and coughing up blood-streaked mucus
  • Deep vein thrombosis. These include leg swelling or pain
  • Other bleeding. These include unexplained bleeding from your nose or gums; an unusually heavy menstrual period; vomit that is bright red or looks like coffee grounds; black, tarry stool or bright red stool; and unexplained abdominal pain

Causes

The role of phospholipids

In antiphospholipid syndrome, your blood clots abnormally because your body mistakenly produces antibodies that attack phospholipids, a type of fat that plays a key role in clotting. Antibodies are proteins that normally protect the body against invaders, such as viruses and bacteria.

You can have antiphospholipid antibodies, but you'll be diagnosed with the syndrome only if they cause health problems. Antiphospholipid syndrome can be caused by an underlying condition, such as an autoimmune disorder, infection or certain medications, or you can develop the syndrome without an underlying cause.

Risk factors

Antiphospholipid syndrome affects women much more than it does men. Other risk factors include:

  • Having an autoimmune condition, such as systemic lupus erythematosus or Sjogren's syndrome
  • Having certain infections, such as syphilis, HIV/AIDS, hepatitis C or Lyme disease
  • Taking certain medications, such as hydralazine for high blood pressure, the heart rhythm-regulating medication quinidine, the anti-seizure medication phenytoin (Dilantin) and the antibiotic amoxicillin
  • Having a family member with antiphospholipid syndrome

Risk factors for developing symptoms

It's possible to have the antibodies associated with antiphospholipid syndrome without developing signs or symptoms. However, having these antibodies increases your risk of developing blood clots, particularly if you:

  • Become pregnant
  • Are immobile for a time, such as being on bed rest or sitting during a long flight
  • Have surgery
  • Smoke cigarettes
  • Take oral contraceptives or estrogen therapy for menopause
  • Have high cholesterol and triglycerides levels

Complications

Depending on which organ is affected by a blood clot and how severe the obstruction of blood flow to that organ is, untreated antiphospholipid syndrome can lead to permanent organ damage or death. Complications include:

  • Kidney failure. This can result from decreased blood flow to your kidneys.
  • Stroke. Decreased blood flow to a part of your brain can cause a stroke, which can result in permanent neurological damage, such as partial paralysis and loss of speech (aphasia).
  • Cardiovascular problems. A blood clot in your leg can damage the valves in the veins, which keep blood flowing to your heart. This can result in chronic swelling and discoloration in your lower legs (chronic venous insufficiency). Another possible complication is heart damage.
  • Lung problems. These can include high blood pressure in your lungs (pulmonary hypertension) and pulmonary embolism.
  • Pregnancy complications. These can include miscarriages, stillbirths, premature delivery, slow fetal growth and high blood pressure during pregnancy (preeclampsia).

Rarely, a person can have repeated clotting events in a short time, leading to progressive damage in multiple organs (catastrophic antiphospholipid syndrome).