Antiphospholipid syndrome (APS)
An autoimmune condition affecting how the blood clots, which can occur on its own or alongside other autoimmune conditions
Antiphospholipid syndrome, or APS, is an autoimmune condition in which the immune system produces antibodies that make the blood more likely to clot. It can lead to clots in the veins or arteries, and in pregnancy it is an important consideration. APS can occur on its own or alongside another autoimmune condition such as lupus, which is why specialist assessment matters.
Written for patients and reviewed by Dr Liubov Borukhson, Consultant Rheumatologist (GMC 7021928). Last clinically reviewed: June 2026.
Common features
APS is recognised mainly through its effects rather than day-to-day symptoms. Features may include:
- Blood clots in the legs, lungs or elsewhere
- Pregnancy complications, including recurrent miscarriage
- Sometimes a lacy purple pattern on the skin, headaches, or other effects
- In some people, features of an associated autoimmune condition
How it is diagnosed
Diagnosis is based on the clinical history, in particular any clots or pregnancy complications, together with blood tests for the relevant antibodies. Because the antibodies need to be present and confirmed on more than one occasion, and because APS overlaps with other autoimmune conditions, careful specialist assessment is important to reach the diagnosis.
How it is managed
Management focuses on reducing the risk of clots, and is highly individual depending on your history. If there has not been a clot, this may mean an antiplatelet medicine such as low-dose aspirin; after a clot, an anticoagulant such as warfarin, or sometimes heparin, is usually used under specialist supervision. Warfarin needs regular blood tests (INR monitoring) to keep it in the right range, and the newer direct oral anticoagulants are generally avoided in APS, so the choice is discussed fully with you. In pregnancy, aspirin is usually combined with heparin injections, with close monitoring and care planned alongside the obstetric team. Where APS occurs alongside another autoimmune condition, that is managed too. The plan is agreed with you.
Coordinated, specialist-led care
Antiphospholipid syndrome affects how the blood clots and can involve several different parts of the body, as well as needing careful planning around pregnancy, so care often draws on more than one specialty, such as haematology and obstetrics. Dr Borukhson practises within a world-renowned tertiary centre, with ready access to consultant colleagues across the other specialties that may be involved in caring for this condition. Where appropriate, she can involve those specialists directly, and bring particularly complex cases to a multidisciplinary team meeting (MDT) with minimal delay. This means that, when more than one area of expertise is needed, your care can be joined up and decisions reached promptly.
Why specialist assessment matters
APS is an important and very manageable condition once recognised, but it needs accurate diagnosis and a tailored plan, particularly around pregnancy or after a clot. If you have had an unexplained clot, recurrent miscarriage, or a positive antibody test, a specialist review can establish whether APS is present and what should be done.
Common questions
How is antiphospholipid syndrome diagnosed?
Diagnosis brings together your history, in particular any blood clots or pregnancy complications, alongside blood tests for the relevant antibodies. Because those antibodies need to be confirmed on more than one occasion, and because APS can overlap with conditions such as lupus, a careful specialist assessment is important to reach the diagnosis. A single test on its own does not settle it.
Is antiphospholipid syndrome curable, or will it go away?
APS is a long-term condition rather than something that clears up, but it is very manageable once it has been recognised. The aim is to reduce the risk of clots and to plan carefully around pregnancy, and most people do well with the right treatment and monitoring. The plan is tailored to your own history and reviewed over time.
I have had a positive antibody test. Does that mean I have APS?
Not on its own. A positive antibody result is only part of the picture, and the antibodies need to be present and confirmed on more than one occasion before APS is diagnosed. The result is always weighed alongside your history, particularly any clots or pregnancy complications, which is why a specialist review is worthwhile to establish whether APS is actually present.
Is antiphospholipid syndrome serious, and do I need to see more than one specialist?
APS is an important condition because it affects how the blood clots and can involve several parts of the body, as well as needing careful planning around pregnancy, but it responds well to treatment once recognised. Care often draws on more than one specialty, such as haematology and obstetrics, so it is helpful to have it coordinated. Dr Borukhson practises within a tertiary centre with ready access to consultant colleagues, so the relevant specialists can be involved promptly and your care kept joined up.
Concerned about clotting or a positive antibody test?
A specialist assessment can establish whether antiphospholipid syndrome is present and agree a tailored plan to reduce risk
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