The triple test is very important for the diagnosis of the cause of anemia, which is now commonly seen clinically as iron deficiency anemia and megaloblastic anemia. The triple test is mainly to check the levels of ferritin, folic acid and vitamin B12 to determine whether the anemia is iron deficiency anemia or megaloblastic anemia. A decrease in ferritin is likely to be iron deficiency anemia, while a decrease in folic acid or vitamin B12 is likely to be megaloblastic anemia. The diagnosis of iron deficiency anemia and megaloblastic anemia can be made based on routine blood tests and triple tests for anemia. However, in some patients with anemia, the triple test may be normal or elevated, and tests such as bone marrow cytology and liver function are usually required to determine the cause of the anemia.