D-dimer is a protein fragment (small piece) that’s made when a blood clot dissolves in the body. Blood clotting is an important process that prevents you from losing too much blood when injured. Normally, the body will dissolve the clot once the injury has healed. With a blood clotting disorder, clots can form when you don’t have an obvious injury or don’t dissolve when they should.
Deep vein thrombosis (DVT), a blood clot that’s deep inside a vein. These clots usually affect the lower legs, but they can also happen in other parts of the body. Pulmonary embolism (PE), a blockage in an artery in the lungs. It usually happens when a blood clot in another part of the body breaks loose and travels to the lungs. DVT clots are a common cause of PE. Disseminated intravascular coagulation (DIC), a condition that causes too many blood clots to form. Stroke, a blockage in the blood supply to the brain.