MEDICAL ANIMATION TRANSCRIPT: You or someone you care about may have been diagnosed with leukemia. This video will help you understand more about this type of cancer and how it affects your body. Your blood contains fluid and three types of cells, red blood cells, white blood cells, and platelets. These cells are made in the spongy center of your bones called bone marrow. All blood cells come from parents cells called stem cells. Red blood cells carry oxygen to your body's tissues. Platelets help your blood to clot and white blood cells help your body fight infections and any other harmful invaders or diseases. Leukemia is a cancer that originates from certain white blood cells while they're forming. In leukemia, the stem cells in the bone marrow make too many abnormal white blood cells that don't work properly. This weakens your immune system. Leukemia may also reduce the amount of platelets and red blood cells. The main types of leukemia are named for the cells they originate from and how quickly they develop. For example, lymphocytic leukemia affects white blood cells called lymphocytes. In this disease, too many lymphoid stem cells develop into abnormal lymphocytes. Myeloid leukemia affects white blood cells called myeloid cells. In this type of cancer, too many myeloid cells become abnormal and divide into abnormal myeloblasts or granulocytes, which are different types of white blood cells. Each type of leukemia can be either acute, which means it progresses quickly or chronic, which means it develops over time. Symptoms for leukemia vary depending on the type of leukemia and which blood cells are affected. Sometimes leukemia has no symptoms but in general, the symptoms may include feeling tired and weak, bruising and bleeding easily, fever, weight loss, and frequent infections. As part of the diagnosis, your doctor will try to find out the size of the cancer tumors and if the cancer has spread. This is called staging. Staging varies with different types of leukemia. In general, an earlier stage or phase means less cancer growth and spread. A higher stage or phase means more cancer growth and spread throughout the body. The cause of leukemia isn't known but there are some things that can increase your risk. Being exposed to high dose radiation, having certain abnormal genes, infection with certain viruses such as the Epstein–Barr virus, longterm exposure to certain chemicals such as benzene and chemotherapy drugs, smoking and older age. As you deal with a diagnosis of leukemia continue to talk to your doctor and your cancer care team.