What Is Leukemia? Leukemia is cancer of the white blood cells. White blood cells (also called leukocytes or WBCs) fight infections and other diseases. In leukemia, the bone marrow (spongy material inside the bones) makes many white blood cells that aren't normal. These abnormal WBCs crowd the bone marrow and get into the bloodstream. Unlike healthy white blood cells, they can't protect the body from infections. Sometimes leukemia (loo-KEE-mee-uh) spreads from the bone marrow to other parts of the body, like the chest, brain, or liver. Leukemia is the most common type of cancer in children. But most kids and teens treated for leukemia are cured of the disease. What Are the Types of Leukemia? Most cases of leukemia in children are: acute lymphoblastic leukemia (ALL), which affects lymphocytes (a type of white blood cell)or acute myeloid leukemia (AML), which affects blast cells (immature white blood cells) Less common types of childhood leukemia include: chronic myelogenous leukemia (CML) juvenile myelomonocytic leukemia (JMML) What Are the Signs & Symptoms of Leukemia? Kids with leukemia may get more viral or bacterial infections than other kids. These happen because their white blood cells can't fight infections. They also may get anemia, which is when there's a low number of red blood cells. This happens because leukemia cells crowd the bone marrow. This prevents bone marrow from making the usual amount of oxygen-carrying red blood cells. Kids with anemia may: look pale feel very tired, weak, or short of breath while playing bruise very easily, get a lot of nosebleeds, or bleed for a long time after even a minor cut Other symptoms of leukemia can include: pain in the bones or joints, sometimes causing a limp swollen lymph nodes (swollen glands) in the neck, groin, or elsewhere poor appetite and weight loss fevers with no other symptoms belly pain Sometimes leukemia can spread, or metastasize. If it spreads to the brain, symptoms may include headaches, seizures, balance problems, or vision problems. If it spreads to the lymph nodes in the chest, symptoms may include breathing problems and chest pain. What Causes Leukemia? Doctors don't know exactly what causes leukemia. But most cases happen when there is a change (mutation) in a gene that happens spontaneously. This means that the genetic mutation was not passed down from a parent. Kids have a greater chance of developing leukemia if they have: an identical twin who had leukemia at a young age a non-identical twin or other siblings with leukemia had radiation therapy or chemotherapy for other types of cancer taken medicines to suppress their immune system after an organ transplant a genetic health problem, such as: Li-Fraumeni syndrome Down syndrome Klinefelter syndrome neurofibromatosis ataxia telangectasia Fanconi anemia Who Gets Leukemia? Leukemia affects adults and children. It is more common in boys than girls. The different types of leukemia affect different age groups: Acute lymphoblastic leukemia (ALL) is most common in children 2 to 8 years old. Acute myelogenous leukemia (AML) can happen at any age, but most cases happen in kids younger than 2 and teens. Chronic myelogenous leukemia is most common in teens. Juvenile myelomonocytic leukemia (JMML) affects infants and toddlers. How Is Leukemia Diagnosed? To find out if a child has leukemia, a doctor will: Ask questions about the symptoms. Do an exam to check for signs of infection, anemia, unusual bleeding, and swollen lymph nodes. Feel the child's belly to check the liver and spleen because leukemia can make these organs get bigger. The doctor also will order some blood tests. Depending on the results, other testing done can include: a bone marrow biopsy spinal tap imaging tests like X-rays genetic testing How Is Leukemia Treated? A pediatric oncologist (a doctor who specializes in childhood cancer) will lead the medical team caring for a child with leukemia. The oncologist works with other specialists, including nurses, social workers, psychologists, and surgeons. Chemotherapy is the main treatment for childhood leukemia. The dosages and drugs used may differ based on the child's age and the type of leukemia. Other treatments include: radiation therapy: high-energy X-rays that kill cancer cells targeted therapy: specific drugs that find and attack cancer cells without hurting normal cells stem cell transplants: putting healthy stem cells into the body Looking Ahead With the proper treatment, the outlook for kids and teens with leukemia is quite good. Most childhood leukemias have very high remission rates, with some up to 90%. Remission means that doctors see no cancer cells in the body. Most kids are cured of the disease. This means that they're in permanent remission. Having a child being treated for cancer can feel overwhelming for any family. But you're not alone. To find support, talk to anyone on the care team or a hospital social worker. Many resources are available to help you and your child. You also can find information and support online at: National Cancer Institute American Childhood Cancer Organization American Cancer Society Back to Articles Related Articles Anemia Anemia is common in teens because they undergo rapid growth spurts, when the body needs more nutrients like iron. Learn about anemia and how it's treated. Read More Anemia Anemia happens when there aren't enough healthy red blood cells in the body. It can be caused by many things, including dietary problems, medical treatments, and inherited conditions. Read More Aspiration and Biopsy: Bone Marrow A bone marrow aspiration and biopsy are performed to examine bone marrow, the spongy liquid part of the bone where blood cells are made. Read More Childhood Cancer Different kinds of childhood cancer have different signs, symptoms, treatments, and outcomes. But today, most kids with cancer get better. Read More Neutropenia Certain cancers, or cancer treatment, can weaken the immune system, requiring a child to stay home to avoid exposure to germs. Here are ways to help your child make the best of it. Read More Stem Cell Transplants Stem cells help rebuild a weakened immune system. Stem cell transplants are effective treatments for a wide range of diseases, including cancer. Read More Stem Cell Transplants Stem cells can develop into cells with different skills, so they're useful in treating diseases like cancer. Read More Cancer Center Cancer is a serious illness that needs special treatment. Find out more about how kids can cope with cancer. Read More What Is Cancer? When kids get cancer, it can often be treated and cured. Find out more in this article for kids. Read More Acute Lymphoblastic Leukemia (ALL) Acute lymphoblastic leukemia (ALL) is the most common type of childhood cancer. Because it develops and gets worse quickly, prompt treatment is very important. With treatment, most kids are cured. Read More Chemotherapy Chemotherapy (chemo) is treatment with medicines that stop the growth of cancer cells. Read More Radiation Therapy Radiation therapy, also called radiotherapy, irradiation, or X-ray therapy, is one of the most common forms of cancer treatment. Read More Chronic Myelogenous Leukemia (CML) While this type of blood cancer is more common in adults, it affects children, too. Thanks to advances in therapy, most kids with CML can be cured. Read More Cancer Center Visit our Cancer Center for teens to get information and advice on treating and coping with cancer. Read More Cancer Center From treatments and prevention to coping with the emotional aspects of cancer, the Cancer Center provides comprehensive information that parents need. Read More Acute Myeloid Leukemia (AML) Acute myeloid leukemia (AML) happens when the body makes too many immature white blood cells. Among kids with leukemia, 20% have this type. With treatment, most recover. Read More Juvenile Myelomonocytic Leukemia (JMML) Learn about this rare type of cancer, which usually affects kids under 4 years old. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.