Leukemia is a type of cancer that affects the bone marrow and its production of leukocytes, or white blood cells. White blood cells normally help fight off infection, but when a patient has leukemia, the bone marrow starts to produce abnormal white blood cells, called leukemia cells. These cells do not function the way normal white blood cells do in assisting the body's immune system.

In addition, leukemia cells grow more quickly than normal leukocytes and don't stop growing when they should. As leukemia progresses, the leukemia cells displace the normal white blood cells which can result in various symptoms, including anemia, infections and excessive bleeding. Leukemia cells are also capable of spreading throughout the body to the lymph nodes or to organs and causing swelling and pain.

Types of Leukemia

There are four main types of leukemia, each classified by how fast the disease progresses and the type of cells affected. The four main types of leukemia are:

  • Acute myelogenous leukemia (AML)
  • Acute lymphocytic leukemia (ALL)
  • Chronic lymphocytic leukemia (CLL)
  • Chronic myelogenous leukemia (CML)

Leukemia is often considered a children's disease, but only some types are common in children and some types of leukemia begin in adulthood or even late in life.

Risk Factors for Leukemia

The cause of most types of leukemia is unknown. Risk factors may include the following:

  • Exposure to high doses of ionizing radiation
  • Genetic abnormalities, including Down syndrome
  • Long-term benzene exposure
  • Smoking
  • Chemotherapy drugs known as alkylating agents

For adult-onset leukemia, exposure to ionizing radiation is the most firmly established environmental risk factor. For children, exposure to ionizing radiation, as well as parental exposure to pesticides and other chemicals, may increase the risk.

Symptoms of Leukemia

Leukemia can cause different symptoms depending on its type, but common symptoms may include:

  • Fever or chills
  • Fatigue and weakness
  • Loss of appetite
  • Shortness of breath
  • Bone or joint pain
  • Bleeding and bruising easily
  • Abdominal pain from an enlarged spleen
  • Swollen lymph glands
  • Recurrent infections

Diagnosis of Leukemia

Leukemia is diagnosed by a combination of the following methods:

  • Physical exam
  • Blood tests
  • Chest X-ray
  • Bone marrow test
  • Cytogenetic testing

Once leukemia is diagnosed, the stage of the disease, or its level of severity, will be determined in order to decide on an appropriate treatment plan. Spinal taps and MRI scans may be used to determine whether the leukemia has spread to other parts of the body.

Treatment of Leukemia

Treatment of leukemia is different from treatment of many other cancers because leukemia is a blood cancer which cannot be treated surgically. There are several different treatment options, the effectiveness of which depends on the type of leukemia, and the age and overall health of the patient. Commonly used treatments for leukemia include the following:

  • Chemotherapy
  • Inhibitors of kinase, an enzyme
  • Radiation therapy
  • Biological therapy
  • Bone marrow transplant
  • Stem cell transplant

Some types of leukemia go into remission for relatively long, or even indefinite, periods of time. While one or another of the above treatments may be very effective, many may have serious side effects, such as increased susceptibility to infection. It is important for leukemia patients to avoid crowds and people with contagious diseases as much as possible. For those diagnosed with leukemia, having a strong support system in place, maintaining a positive outlook on life, exercising on a regular basis and eating healthful, balanced meals will help in coping with the disease.

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