A leukemia blood test is abnormal for several things, such as an abnormally high or low white blood cell count, a low red blood cell count, a low platelet count Leukemia 1. Abnormally high white blood cell count: common in acute leukemia, chronic granulocytic leukemia, chronic lymphocytic leukemia and chronic monocytic leukemia, etc. Most of them can have a sharp increase or decrease of white blood cells, and patients will have headache, chest tightness, fatigue and other symptoms. 2. Decreased red blood cell count: severe anemia often occurs in leukemia. 3. Decrease in platelet count: Decrease in megakaryocytes in bone marrow usually leads to decrease in platelet production, which will make the patient bleed easily. If you notice any abnormalities in your blood count or any discomfort, it is recommended that you go to the hospital in a timely manner.