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. Their main job is to help 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, called a growth or tumor. The term cancer refers to malignant growths. These growths can invade nearby tissues. Cancer that has invaded nearby tissues can then spread to 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 chance of leukemia include:

  • Exposure to some environmental and chemical factors such as:
  • 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
  • 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 blood cells in:

  • Blood tests
  • Bone marrow biopsy —a sample of bone marrow is removed to test for cancer cells

Imaging tests may be done to look for infections or injuries caused by leukemia including:


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

Treatment that targets the leukemia itself 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. 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 alone or with chemotherapy.


High doses of radiation and/or chemotherapy can destroy immature healthy blood cells. Transplantation will help the body build healthy cells again. 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 exact cause is unknown.