Your doctor might suspect you have leukemia from your symptoms and your physical exam. But, you'll need some tests to confirm the diagnosis. Leukemia is cancer of your white blood cells, and there are different types. Your doctor will need to know the type of leukemia you have, and whether it has spread. This information is important for choosing the best treatment. History and Physical Exam Your doctor will probably ask you about symptoms. Have you had fevers, chills, frequent infections, or bleeding? Have you been more tired than usual? Lost weight? Do you have night sweats or bone pain? Then, during a physical exam, your doctor will look for certain signs. These include bruising, enlarged lymph nodes, red spots under your skin, bleeding gums, and an enlarged spleen or liver. Blood Tests Leukemia affects immature white blood cells. These are bloods cells that are just developing. It causes them to multiply inside the spongy center of your bones, called the bone marrow. The leukemia cells multiply faster than other blood cells that are also developing. Leukemia cells can crowd out the other cells and cause changes in your blood. Blood tests you may have include: Complete blood count (CBC). This test checks the number of red blood cells, white blood cells, and clotting cells called platelets. Leukemia may cause high numbers of some white blood cells and low numbers of red cells and platelets. Peripheral smear. This test involves checking your blood cells under a microscope. Leukemia cells look abnormal. Bone Marrow Tests Bone marrow is where leukemia starts. Bone marrow testing involves putting a needle into the center of a bone to remove cells or a small piece of bone marrow. Doctors usually use the hip bone for this test. Bone marrow testing helps reveal the type of leukemia and how advanced it is. A doctor, called a pathologist, will look at the bone marrow cells under a microscope. The pathologist examines the size, shape and maturity of the cells. Chromosome Testing Chromosomes are DNA bundles inside your cells. Doctors can use chromosome testing on blood cells or bone marrow cells to look for changes that develop with some types of leukemia. This testing also helps doctors learn about the type of leukemia and how it may respond to treatment. For instance, people with a common type of leukemia—called acute lymphocytic leukemia, or ALL—may have an abnormal chromosome. It's called the Philadelphia chromosome. People with another common type—chronic lymphocytic leukemia, or CLL—are missing parts of some chromosomes. Tests to Look for Leukemia Outside the Bone Marrow and Blood Leukemia that has spread outside of bone marrow and blood may be treated differently. Leukemia can spread to your lymph nodes, brain, spinal cord, spleen, or liver. Tests to look for leukemia that has spread include: Imaging studies. These tests look for leukemia in many areas of the body. For instance, a chest X-ray may show leukemia lymph nodes in the chest. A CT scan may show signs of leukemia in the spleen or liver. An MRI is another way to look for signs of leukemia in the brain or spinal cord. Ultrasound imaging uses sound waves to look for leukemia lymph nodes inside the abdomen. Lumbar puncture. This test removes fluid from around the spinal cord. The fluid is cerebrospinal fluid (CSF). It surrounds the brain and spinal cord. Doctors test the fluid for leukemia cells. Lymph node biopsy. This is surgery to remove a lymph node. Doctors use a microscope to look for leukemia cells in the lymph node. Once your doctor has diagnosed leukemia and learned about the type and extent of your disease, you can start talking about treatment. Getting the right diagnosis is the first step toward recovery.