When diagnosing leukemia, your doctor will perform tests to confirm the diagnosis. Tests and exams used to diagnose leukemia commonly include:
Physical exam — Your doctor will check your lymph nodes, spleen, and liver to see if they are enlarged or swollen.
Blood tests  — Your doctor will look at a sample of your blood to see if you have a high white blood cell count, which can be a sign of leukemia.
Bone marrow tests — A sample of your bone marrow may be analyzed to see what types of leukemic cells are present.
Your doctor may perform additional tests to determine the type of leukemia or the stage it is in. The results of these tests and exams will determine the course of treatment.