Antiphospholipid syndrome

Also called APS, Hughes syndrome, or "Sticky blood"

Antiphospholipid syndrome is an autoimmune condition in which the immune system makes antibodies that make the blood more likely to clot. This can lead to clots in the legs or lungs, strokes, and repeated miscarriages or other pregnancy problems. With treatment, most people lead normal lives.

Last updated Nov 9, 2026

What it is

It can occur on its own or alongside other autoimmune conditions such as lupus.

Treatment usually involves blood-thinning medicines, sometimes lifelong. In pregnancy, specific treatment and close monitoring greatly improve the chances of a healthy birth.

Common signs

  • Blood clots in the legs (DVT) or lungs
  • Stroke or mini-stroke at a young age
  • Repeated miscarriages or other pregnancy complications
  • A lacy, net-like rash on the skin

How it is usually diagnosed

  • Blood tests for antiphospholipid antibodies, repeated at least 12 weeks apart
  • Scans to confirm clots

Records worth keeping

Keeping these together makes each appointment easier, especially when you see a new doctor:

  • Antibody test results with dates
  • Reports of every clot and how it was found
  • Anticoagulation records (INR results if on warfarin)
  • Pregnancy and obstetric notes

Questions to ask your doctor

  • How long will I need blood thinners?
  • What should I do before surgery, travel or pregnancy?
  • Which medicines, including the pill, should I avoid?

When to get help right away

Call 112 or go to the nearest emergency department if you have:

  • A painful, swollen leg, or sudden breathlessness or chest pain
  • Signs of a stroke: face drooping, arm weakness, slurred speech
  • Heavy bleeding while on blood thinners

This page is general information. It is not a diagnosis and does not replace a doctor who knows your history. Medfold keeps your records organised; it does not interpret them.

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