How is the condition diagnosed?

Diagnosis begins with the history and physical exam. Blood tests are used to confirm the diagnosis. A blood test called a complete blood count, or CBC, will show a lower-than-normal amount of hemoglobin in the blood. The number of red blood cells may also be low. Looking at blood cells with a microscope can help figure out the cause in some cases. The size and shape of the blood cells often changes based on the type of anemia.

Other blood tests may also be done, depending on the suspected cause. For example, the blood level of iron, folate, or vitamin B12 can be checked if these causes are suspected.

The stool may also be tested to check for blood loss. This is known as a fecal occult blood test. Other blood, urine, or imaging tests may also be used.

In some cases, a procedure called bone marrow biopsy may be advised. This involves inserting a special needle through the skin of the buttocks into the back of the hipbone. The needle is pushed into the middle of the bone, which contains bone marrow. A sample of marrow is taken out with the needle. The sample is then sent to the lab for examination and other testing.