D-Dimer is a type of protein which is produced when a blood clot dissolves in the body. D-Dimer is normally undetectable unless the body is forming or breaking down the blood clots and the level of D-Dimer rises in the blood. To check the level of D-Dimer in the blood, D-Dimer test is conducted. D-Dimer test is used in a hospital emergency room setting to determine if the person is at intermediate or low risk for thrombosis or thrombotic embolism. A negative D- Dimer test indicates that it is highly unlikely that a thrombus is present. Also, a positive D-Dimer test cannot detect whether a blood clot is present or not and indicates that further testing is required. A blood clot can cause health problems like Stroke, Deep Vein Thrombosis, Disseminated Intravascular Coagulation or Deep Vein Thrombosis.