Venous means related to the veins. A thrombosis occurs when a blood vessel which carries blood around the body gets blocked by a blood clot (a thrombus). If a blood clot dislodges from where it was formed and travels in the blood until it becomes stuck in a narrower blood vessel elsewhere in the body, it is called an embolus.
A deep vein thrombosis (DVT) is a blood clot that forms in the deep leg veins that run through the muscles of the calf and thighs.
A DVT can partially or completely block the blood flow in the vein causing symptoms of pain, tenderness, and swelling of the calf which can sometimes become warm and red. In some situations there are no symptoms and a DVT is only diagnosed if a complication occurs such as a pulmonary embolism.
A pulmonary embolism (PE) is where some of the clot from a DVT breaks off and travels to the narrower vessels of the lungs where it gets stuck, blocking the blood flow to a part of the lung. Symptoms of a PE include chest pain and breathlessness and need urgent treatment. If you experience any of these symptoms, you must seek medical attention immediately – call 999.
Venous thromboembolism (VTE) is a word used to describe both DVTs and PEs.