Blood clotting is a biological process that stops excessive bleeding when a blood vessel is injured. However, too much clotting inside your body can lead to many life-threatening conditions. Thus, the human body produces some proteins to help regulate this process. Antithrombin III is one such protein that acts as a blood thinner and helps control blood clotting.  A blood test can detect the amount of Antithrombin III in your body. Specifications of Antithrombin III Test The antithrombin III blood test is done to determine the actual cause behind abnormal blood clots inside your body. If you develop frequent blood clots, it can indicate a deficient antithrombin III or other clotting factors within your body. This deficiency can result from other health problems like liver or kidney disease.  Consequently, it can affect your body's ability to produce enough antithrombin III protein. Deficiency can also result if your body uses excess protein and genetic mutations. The results of the antithrombin III blood test help determine whether you have normal levels of antithrombin in the body. Lower levels of antithrombin III can indicate an antithrombin deficiency, which makes you more likely to develop deep vein thrombosis (DVT) and other conditions such as phlebitis, thrombophlebitis, pulmonary embolus, and heart attack. Who Should Get Tested? An antithrombin III test is advised when blood clots are formed in your blood vessels. People with blood clotting disorder due to antithrombin III deficiency are at increased risk of developing abnormal blood clots in veins. Taking this test early in the ailment will help you diagnose your condition correctly and seek the proper treatment sooner, decreasing your danger substantially.