Trombosis is a medical condition where a blood clot, known as a thrombus, forms in a blood vessel. This can occur in veins or arteries and may block blood flow, leading to serious health issues. Common types include deep vein thrombosis (DVT), which usually occurs in the legs, and arterial thrombosis, which can affect the heart or brain. The formation of a thrombus can be triggered by various factors, such as prolonged inactivity, injury to a blood vessel, or certain medical conditions. If a thrombus breaks loose, it can travel through the bloodstream and cause a pulmonary embolism or a stroke, making timely diagnosis and treatment essential.