How is APS diagnosed?

APS is usually diagnosed from a combination of a positive blood test and symptoms.

If you are under 50 and have suffered a thrombosis causing a deep vein thrombosis (DVT) or a pulmonary embolism (PE), or have had a transient ischemic attack (TIA), stroke or heart attack, particularly more than once, or have had more than one miscarriage or late pregnancy loss, you should discuss with your doctor whether you need the blood tests.

Until 2016, screening for antiphospholipid antibodies (aPL) was not automatically carried out in people who have young (aged under 50) strokes. However, APS Support UK approached the team responsible for updating the National Stroke Guidelines in October 2016. We wrote the section on testing for aPL in stroke survivors that is now included in the Royal College of Physicians National Stroke Guidelines.

Nevertheless, testing for aPL in people who have suffered a DVT or heart attack can still be arbitrary, and women have to go through three consecutive miscarriages before they are tested. Our charity would like to change this in the UK so people are routinely screened when they have thrombosis or have more than one miscarriage.

It is important to inform your doctor about any previous clotting or pregnancy problems and less specific clues such as headaches, migraines, visual disturbances, memory loss, dizziness and fatigue. Family history will also help your doctor reach a diagnosis, so remember to list any immediate family with an autoimmune disease or history of thrombosis. We recommend that you print out our fact sheet: Diagnosis: how to get tested, and take it with you to your appointment.

If your doctor makes a diagnosis based on the positive blood test and symptoms, they will likely refer you to a specialist. The particular type of specialist can depend from hospital to hospital throughout the UK, but you will likely see either a haematologist or a rheumatologist. Most early pregnancy units will have a specialist to treat women with APS.

Our charity maintains the only national directory of APS specialists throughout the UK, based on recommendations we receive from patients.