When blood thickens and forms a semi-solid mass inside a vein, it’s called a thrombus. The medical term for a blood clot that forms in the deep veins, usually in the thigh, pelvis, or calf, is deep vein thrombosis (DVT).

DVT can become dangerous if part of the clot breaks loose and travels through the bloodstream to the lungs. When this happens, it can block a pulmonary artery—a condition known as pulmonary embolism (PE)—which is a medical emergency that can be fatal if not treated right away.

Below, we explore ten important warning signs that might indicate a blood clot is forming in your leg. Early detection and