The aPTT is one of several blood coagulation tests. It measures how long it takes your blood to form a clot. When one of your blood vessels is damaged, proteins called clotting factors come together to form clots and quickly stop the bleeding. The aPTT test helps assess how well those clotting factors work, often in conjunction with other tests that monitor clotting factors.
A blood smear is a sample spread on a glass slide and treated with a special stain. Previously, all blood smears were examined under a microscope by laboratory professionals. Now automated digital systems can help examine blood smears. A blood smear helps diagnose and monitor conditions such as blood disorders, sudden kidney failure, and certain cancer treatments.
A blood type can be classified into four common groups known as the ABO system: A, B, AB, or O. A second system, the Rh system, determines if the blood type is Rh-positive or -negative. Blood typing is a common test before blood transfusions, tissue transplants, and during pregnancy.
A complete blood count is a common blood test in routine checkups. This test can help detect various disorders, including infections and anemia. A reticulocyte count measures the number of immature red blood cells (reticulocytes) in your bone marrow to find out if you are producing enough red blood cells.
The direct Coombs test detects antibodies stuck to the surface of red blood cells. Many diseases and drugs can cause this to happen. These antibodies sometimes destroy red blood cells, causing anemia. Your healthcare provider may recommend this test if you have signs or symptoms of anemia or jaundice (yellowing of the skin or eyes).
Prothrombin is a protein from your liver that acts as a clotting (coagulation) factor. If your blood clots too slowly, you may bleed excessively after an injury. If your blood clots too fast, the clots may harm your heart or brain. A prothrombin time (PT) test measures how long it takes for a clot to form.