Antiphospholipid syndrome (APS) is an autoimmune condition associated with an increased tendency to develop blood clots and, in some people, pregnancy-related complications. It occurs when the immune system produces antiphospholipid antibodies that can affect normal blood-clotting processes. Diagnosis typically considers a person’s clinical history together with blood testing for relevant antibodies, with persistent antibody positivity required in established classification criteria. Treatment is individualized and may include anticoagulant therapy to reduce the risk of future clots. People with APS should receive ongoing care from an appropriate healthcare professional, particularly when planning pregnancy or managing other clotting risk factors. Symptoms such as sudden chest pain, difficulty breathing, severe headache, or one-sided weakness can indicate an emergency and require immediate medical attention.