Your immune system can turn against your blood, triggering dangerous, unprovoked clotting events.

Health · Published 3 October 2026 Swipe more like this →

In short: Antiphospholipid syndrome is an autoimmune condition where the body produces antibodies that attack proteins bound to phospholipids. This process makes blood significantly more likely to clot, leading to risks like stroke, deep vein thrombosis, and pregnancy complications. While there is no cure, lifelong management can prevent life-threatening events.

Antiphospholipid syndrome (APS) occurs when the immune system mistakenly creates abnormal antibodies—specifically lupus anticoagulant, anticardiolipin, or anti-beta-2 glycoprotein 1—that target proteins attached to phospholipids. These phospholipids are essential components of cell membranes. By attacking them, the immune system inadvertently triggers the coagulation system, causing blood to clump and form clots in arteries and veins. These clots can block blood flow to vital organs, including the brain, heart, lungs, and kidneys, leading to severe outcomes like strokes, heart attacks, and pulmonary embolisms.

The condition is categorized as primary when it occurs independently, or secondary when it develops alongside other autoimmune diseases like systemic lupus erythematosus. While the exact trigger for this immune malfunction remains unknown, researchers have identified several risk factors. Women are more frequently affected than men, and individuals between 30 and 40 years old face a higher likelihood of diagnosis. Genetics are also believed to play a role, as the condition can run in families. Lifestyle factors, such as smoking, prolonged immobility, and the use of estrogen-based contraceptives, can further elevate the risk of clotting in those who carry the antibodies.

Diagnosis typically requires a combination of clinical evidence—such as a history of unexplained blood clots or repeated miscarriages—and two positive blood tests spaced at least three months apart. Although there is no cure, the standard treatment involves lifelong use of anticoagulant medications like warfarin to thin the blood and prevent future clots. A rare and severe manifestation known as catastrophic antiphospholipid syndrome (CAPS) can cause widespread organ failure within days; while fatal in nearly half of those who experience it, CAPS affects fewer than 1% of all APS patients. For most, consistent medical monitoring and lifestyle adjustments, such as maintaining a healthy weight and staying hydrated, allow for effective management of the condition.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

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