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 are:

White Blood Cells
Immune system white blood cell

Leukemia cells outnumber healthy white blood cells and gather in spleen and lymph nodes.

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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 chances of leukemia:

  • Current or past smoking is strongly associated with AML. Risk is compounded by how much you smoked and for how long.
  • Age:
    • AML and CLL are most common in adults over 60 years.
    • ALL is most common in children.
  • Chemotherapy for previous cancer.
  • Some genetic diseases, such as Down syndrome.
  • Chronic exposure to benzene that exceeds federally approved safety limits.
  • Previous radiation therapy.
  • Myelodysplastic syndrome —A blood disease, which increases risk for AML.


Leukemia may cause:

  • Fever or night sweats
  • Flu-like symptoms
  • Minor cuts that heal slowly
  • Excessive reaction to insect bites
  • Feeling weak or tired
  • Headache
  • Pale skin
  • Bleeding and bruising easily
  • Nosebleeds
  • Bleeding gums
  • Tiny red spots under the skin

Excess leukemia cells can gather in different parts of the body and organs creating:

  • Pain in the bones or joints
  • Puffy gums
  • Rash
  • Difficulty breathing
  • Swelling of the testicles
  • Swelling or discomfort in the abdomen (from enlarged spleen)
  • Swollen lymph nodes (particularly in neck or armpit)
  • Weight loss
  • Meningitis with headache, nausea, loss of muscle control, seizures, symptoms of stroke


Your doctor will ask about your symptoms and medical history. A physical exam will be done. The doctor will check for swelling of the liver, spleen, or lymph nodes in the armpits, groin, and neck.

Tests may include:

  • Blood tests—to look for leukemia cells in blood
  • Bone marrow aspiration and biopsy —the removal of a sample of bone marrow to look for cancer cells

If cancer cells are found, additional tests may be done. These tests check if the cancer has spread and what systems may already be affected.


The goal for acute leukemia is to destroy all signs of the disease and return the blood and bone marrow to normal. Chronic leukemia is rarely curable. Treatment focuses on slowing disease progression.

Talk with your doctor about the best treatment plan for you. Options include the following:


  • Imatinib mesylate—used to treat myeloid leukemia by reducing the number of cancer cells in the blood and bone marrow
  • Nilotinib—targeted therapy similar to imatinib
  • Dasatinib—targeted therapy similar to imatinib (if leukemia cells become resistant to imatinib)

These drugs can cause infertility and early menopause. Talk to your doctor about your fertility preservation options before you start treatment.

Your doctor may prescribe medications to stimulate the production of healthy blood cells.


Chemotherapy is the use of drugs to kill cancer cells. It may be given in many forms including pill, injection, and through an IV. The drugs enter the bloodstream and travel through the body killing mostly cancer cells. Some healthy cells are killed as well. The specific combination of drugs will depend on the type of leukemia, your age, and condition.

Radiation Therapy

Radiation therapy is a type of treatment that uses radiation to kill cancer cells. Typically, it is only used to prepare for a bone marrow transplant or in some cases of chronic leukemia.


  • Blood transfusions —Healthy blood cells from a donor are given through an IV. This may be done if the leukemia is causing shortness of breath, fatigue, or severe bleeding.
  • Bone marrow transplant —Stem cells from a donor’s healthy bone marrow are injected in you. Stem cells can make all types of blood cells. Once injected into your bloodstream, the stem cells should make healthy blood cells.
  • Splenectomy —The spleen may need to be removed if it becomes congested with leukemia cells or causes complications.

Biological Therapy (Immunotherapy)

The therapy uses medications or substances made by the body to improve your body’s defense against cancer. This type of treatment is still fairly new and under investigation. Talk with you doctor about whether this treatment is an option for you and about clinical trials in your area.


To help reduce your chances of leukemia:

  • If you smoke, talk to your doctor about how you can successfully quit
  • Avoid exposure to benzene
  • Avoid exposure to high levels of radiation when possible

American Cancer Society

Leukemia & Lymphoma Society


Canadian Cancer Society

Provincial Health Services Authority


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Leukemia. EBSCO DynaMed Plus website. Available at: Accessed January 8, 2018.

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Leukemia. National Cancer Institute website. Available at: Accessed January 8, 2018.

A PET scan may improve leukemia care. UW HealthAvailable website. Available at: Accessed January 8, 2018.

8/26/2014 DynaMed Plus Systematic Literature Surveillance Fircanis S, Merriam P, Khan N, Castillo JJ. The relation between cigarette smoking and risk of acute myeloid leukemia: an updated meta-analysis of epidemiological studies. Am J Hematol. 2014;89(8):E125-E132.

Last reviewed November 2018 by EBSCO Medical Review Board Mohei Abouzied, MD, FACP  Last Updated: 12/20/2014