Normal D-dimer blood test readings are values below or equal to 250 nanograms per milliliter D-dimer units, or below or equal to 0.50 micrograms per milliliter fibrinogen-equivalent units, according to Mayo Medical Laboratories. Physicians use the test to negate diagnoses of deep vein thrombosis or pulmonary embolism.
A normal or negative D-dimer result means that the patient is probably not suffering from a disease or condition that is creating abnormal blood clots, explains Lab Tests Online. Positive test results can occur after infection, injury, surgery, heart attack and liver disease when fibrin has formed and broken down but not cleared from the body. A high positive D-dimer test result can also confirm a diagnosis of disseminated intravascular coagulation, which is abnormal internal blood clotting and bleeding.