Blood smear: Drops of blood are smeared across a microscope slide, to be examined by an expert in a lab. Leukemia, anemia, malaria, and numerous other blood conditions can be identified with a blood smear.
Blood type: A test for compatibility before receiving a blood transfusion. The major blood types (A, B, AB, and O) are determined by the protein markers (antigens) present on the surface of red blood cells.
Coombs test: A blood test looking for antibodies that could bind to and destroy red blood cells. Pregnant women and people with anemia may undergo Coombs testing.
Blood culture: A blood test looking for infection present in the bloodstream. If bacteria or other organisms are present, they may multiply in the tested blood, allowing their identification.
Mixing study: A blood test to identify the reason for blood being "too thin" (abnormally resistant to clotting). The patient's blood is mixed in a tube with normal blood, and the mixed blood's properties may provide a diagnosis.
Bone marrow biopsy: A thick needle is inserted into a large bone (usually in the hip), and bone marrow is drawn out for tests. Bone marrow biopsy can identify blood conditions that simple blood tests cannot.
Chemotherapy: Medicines that kill cancer cells. Leukemias and lymphomas are usually treated with chemotherapy.
Blood transfusion: A blood donor's red blood cells are separated from their plasma and packed into a small bag. Transfusing the concentrated red blood cells into a recipient replaces blood loss.
Platelet transfusion: A blood donor's platelets are separated from the rest of blood and concentrated into a plastic bag. Platelet transfusion is generally only performed when platelet counts fall to very low levels.
Fresh frozen plasma: A blood donor's plasma (liquid blood) is separated from the blood cells, and frozen for storage. Plasma transfusion can improve blood clotting and prevent or stop bleeding that's due to clotting problems.
Cryoprecipitate: Specific proteins are separated from blood and frozen in a small volume of liquid. Cryoprecipitate transfusion can replace specific blood clotting proteins when their levels are low, such as in people with hemophilia.
Anticoagulation: Medicines to "thin" the blood and prevent clotting in people at high risk from blood clots. Heparin, enoxaparin (Lovenox) and warfarin (Coumadin) are the medicines most often used.
Antiplatelet drugs: Aspirin and clopidogrel (Plavix) interfere with platelet function and help prevent blood clots, including those that cause heart attacks and strokes.
Antibiotics: Medicines to kill bacteria and parasites can treat blood infections caused by these organisms.
Erythropoietin: A hormone produced by the kidney that stimulates red blood cell production. A manufactured form of erythropoietin can be given to improve the symptoms of anemia.
Bloodletting: In people with problems caused by too much blood (such as from hemochromatosis or polycythemia), occasional controlled removal of blood may be necessary.