Thromboembolism

Key facts

• Thromboembolism happens when a blood clot (thrombus) forms inside a blood vessel, then either grows large enough to block it or breaks free and lodges elsewhere.
• The two most common patterns are deep vein thrombosis (DVT), usually in the leg, and pulmonary embolism, where a clot reaches the lungs.
• Risk rises with prolonged immobility (long flights, bed rest), surgery, hospitalisation, cancer, pregnancy, and inherited clotting disorders.
• Treatment and prevention rely on anticoagulants such as warfarin; new or worsening symptoms need urgent medical attention.

Why clots form and who is at risk

Clots develop when normal blood flow is disturbed, a vessel wall is damaged, or the blood itself clots too readily. Prolonged immobility, long flights or long periods of bed rest, is a frequent trigger. Surgery, hospitalisation, cancer, pregnancy, and certain inherited clotting disorders all raise the risk significantly.

Recognising a clot in time

Deep vein thrombosis typically causes swelling, warmth, and aching in one leg. A pulmonary embolism can produce sudden breathlessness, chest pain, or coughing up blood. These symptoms need urgent medical attention: call emergency services or go to the nearest hospital without delay if they appear.

Reducing clot risk with anticoagulation

The mainstay of treatment and prevention is anticoagulation, medicines that reduce the blood's tendency to clot. Warfarin is a well-established oral anticoagulant used both for treating existing thromboembolism and for long-term prevention in higher-risk patients. Dosing requires careful monitoring, because the effective range is narrow and interactions with diet and other medicines are common.

Anticoagulation sits within broader heart and blood pressure management, reflecting how closely clot risk ties to overall cardiovascular health. Anyone starting or adjusting an anticoagulant should discuss other medicines, supplements, and planned procedures with their doctor or pharmacist first, since interactions can raise bleeding risk or reduce protection.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.