Leukemia is a cancer of the blood cells. In cancer, cells become abnormal and grow out of control. As the number of abnormal blood cells increase, the healthy blood cells are outnumbered. There are three main types of blood cells. Each has a distinct job:

  • White blood cells (WBC), also called lymphocytes, are most often involved in leukemia. WBCs are components of the immune system.
  • Red blood cells (RBC) carry oxygen throughout the body.
  • Platelets help the blood clot at injury sites.

Leukemia cells cannot do the job of normal blood cells. This causes many of the symptoms of leukemia. The disease starts in the bone marrow where blood cells are made. The most common types of leukemia in children are:

White Blood Cells
White Blood Cells

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Cancer occurs when cells in the body divide without control or order. Normally, cells divide in a regulated manner. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue forms. The term cancer refers to malignant growth of cells or tissue. These growths can invade nearby tissues. Cancer that has invaded nearby tissues can then spread to the blood and other parts of the body.

It is not clear exactly what causes these problems in the cells, but it is probably a combination of genetics and environment.

Risk Factors

Factors that may increase your child's chances of leukemia:

  • Exposure to some environmental and chemical factors such as:
    • Chronic exposure to benzene that exceeds federally approved safety limits.
    • Some chemotherapy drugs
    • High doses of radiation therapy
  • Having a sibling, especially an identical twin, who develops leukemia
  • Having a genetic condition, such as Down syndrome, Li-Fraumeni syndrome, Klinefelter syndrome, Wiskott-Aldrich syndrome, ataxia-telangiectasia, neurofibromatosis, or Fanconi anemia


Leukemia may cause:

  • Bleeding or bruising—may appear as tiny red spots
  • Acute or recurrent infections—may have fever, chills, and a cough
  • Bone and joint pain
  • Abdominal pain
  • Weight loss, loss of appetite
  • Swollen lymph nodes, swelling of the liver or spleen
  • Difficulty breathing
  • Rash, gum problems
  • Weakness and fatigue
  • Pale skin
  • Shortness of breath
  • Decreased energy


The doctor will ask about your child’s symptoms and medical history. A physical exam will be done. The doctor will check for swelling of the liver, spleen, and lymph nodes. Leukemia can be diagnosed by identifying abnormal cells in the blood. Further testing is done to identify specific details and locations of the lymphocytic cells to determine treatment. Tests include:

  • Blood tests—to measure the number and type of blood cells
  • Bone marrow biopsy —a sample of bone marrow is removed and tested for the presence of cancer
  • Lumbar puncture —tests the fluid that surrounds the brain and spinal cord for the presence of cancer

Imaging tests may be done to look for spreading of the tumor, infections, or injuries caused by leukemia:


Symptoms created by leukemia may need to be treated first. Treatment may include:

  • Antibiotics to treat infections
  • Blood transfusion to treat severe anemia or bleeding
  • Emergency treatment if there are too many leukemia cells or the leukemia cells are dying too quickly

Treatment is determined by the specific type of leukemia cell identified by testing. Treatment may one or a combination of the treatments below:


Chemotherapy is the use of drugs to kill cancer cells. The drugs enter the bloodstream and travel through the body killing mostly cancer cells. Multiple are used at the same time, in various combinations. Chemotherapy may be used alone or with other treatments like radiation therapy.

Radiation Therapy

Radiation therapy is directed to a specific area to kill the cancer cells. May be used during or after chemotherapy for cancer in specific locations, such as in the central nervous system.


High doses of radiation and/or chemotherapy can destroy immature healthy blood cells. Transplantation will help the body build healthy cells again if all bone marrow is destroyed. Transplantation may also be used in children with poor response to or inability to tolerate chemotherapy, poor-risk disease with high-risk of relapse, or after relapse. Treatment is given to remove all the existing bone marrow cells before new bone marrow or stem cells are given.

Transplant options may include bone marrow or stem cell transplantation.

  • In bone marrow transplantation, the marrow may be removed, treated to kill cancer cells, and frozen. After treatment, the bone marrow is placed back into the body. The marrow may also be provided from a healthy donor. The marrow with leukemia will be removed and the donated marrow will be delivered after treatment.
  • Peripheral blood stem cell transplantation uses immature cells that are found in the blood. These cells are removed from the blood before chemotherapy or radiation treatment. Once treatment is done, the stem cells are then placed back into the blood. The immature cells will grow into healthy white and red blood cells.

Other Treatments

  • Biological therapy uses medication or substances made by the body to increase the body’s natural ability to fight cancer.
  • Certain medication or therapies may also be used to help manage the side effects of treatment.
  • During treatment and recovery your child may need to take steps to avoid infections. Treatments and the cancer can weaken the immune system and make the child more vulnerable to bacteria and viruses.


There are no current guidelines to prevent leukemia in children because the cause is unknown.


American Cancer Society

Leukemia & Lymphoma Society


Canadian Cancer Society

Provincial Health Services Authority


Acute lymphoblastic leukemia/lymphoma (ALL). EBSCO DynaMed Plus website. Available at: Updated October 13, 2017. Accessed January 8, 2018.

Childhood cancers. National Cancer Institute website. Available at: Updated August 30, 2017. Accessed January 8, 2018.

Leukemia. Leukemia & Lymphoma Society website. Available at: Accessed January 8, 2018.

Leukemia in children. American Cancer Society website. Available at: Accessed January 8, 2018.

Leukemia in children. Boston Children's Hospital website. Available at: Accessed January 8, 2018..

Last reviewed November 2018 by EBSCO Medical Review Board Mohei Abouzied, MD, FACP  Last Updated: 11/9/2015