A risk factor is something that increases your likelihood of getting a disease or condition. It is possible to develop leukemia with or without the risk factors listed below. However, the more risk factors you have, the greater your likelihood of developing leukemia. If you have a number of risk factors, ask your doctor what you can do to reduce your risk.

The list below is a general list of risk factors that cover most types of leukemia.

Leukemia is most common in adults aged 60 years and older. The exception is acute lymphoblastic leukemia (ALL), which occurs most often in children under 8 years old. Males have a slightly higher risk of leukemia than females.

Other factors that may increase the chance of leukemia include:

Occupational and Environmental Exposures

Exposure to benzene is strongly associated with leukemia. Benzene is a chemical that can be inhaled or absorbed through the skin. Some common sources of benzene include gasoline, wood smoke, tobacco smoke, exhaust from automobiles, and well water. It is also used to make plastics, nylon fibers, dyes, and pesticides. Certain careers and activities have a higher risk of exposure to benzene, especially if proper precautions are not followed.

People who have survived nuclear accidents or explosions are also at an increased risk. Fallout from nuclear radiation stays in the environment for years.

Medical Treatment

Some medical treatments are associated with an increased risk of leukemia. These may include:

  • Radiation from medical and dental procedures
  • History of organ transplantation and medications to suppress the immune system
  • History of prior cancer treatment with chemotherapy (rare)
  • Most exposure are a necessary part of treatment, but work with your doctor to limit your exposure to unnecessary testing that may expose you to radiation.


    Certain genetic defects are associated with leukemia. For example, chronic lymphocytic (CLL) and acute myeloid leukemias (AML) in a first degree relative (brother, sister, parent) increase the risk of developing leukemia.

    Certain medical conditions are cause by specific genetic abnormalities. These genetic changes may also increase the risk of leukemia. Genetic conditions that have a higher than average risk for leukemia include:

  • Down syndrome
  • Klinefelter syndrome
  • Li-Fraumeni syndrome
  • Wiskott-Aldrich syndrome
  • Ataxia-telangiectasia
  • Neurofibromatosis
  • Fanconi anemia
  • Smoking

    Smoking introduces a variety of harmful chemicals into the body that can affect the DNA of cells. Current or past smoking is strongly associated with AML and chronic myeloid leukemia (CML). Risk increases with the number of cigarettes smoked and years as a smoker.