Lupus diagnosis is difficult. No one test can diagnose lupus. Doctors need a combination of blood tests, imaging tests, physical exams to get the diagnosis. The blood and urine tests can include: Complete blood count. This test measures the number of red blood cells, white blood cells and platelets as well as the amount of hemoglobin, a protein in red blood cells. Results may indicate you have anemia, which commonly occurs in lupus. A low white blood cell or platelet count may occur in lupus as well. Erythrocyte sedimentation rate. This blood test determines the rate at which red blood cells settle to the bottom of a tube in an hour. A faster than normal rate may indicate a systemic disease, such as lupus. The sedimentation rate isn't specific for any one disease. It may be elevated if you have lupus, an infection, another inflammatory condition or cancer. Kidney and liver assessment. Blood tests can assess how well your kidneys and liver are functioning. Lupus can affect these organs. Urinalysis. An examinat