Leukemia is a type of cancer that starts in immature blood cells in the bone marrow. Doctors typically use blood tests alongside other medical tools to diagnose leukemia.

Leukemia accounts for around 3.2% of all cancer diagnoses in the United States. There are several types of leukemia, and they can be acute or chronic.

Most leukemias begin in cells that become white blood cells, but some forms of leukemia can develop in other blood cell types.

Keep reading to learn more about leukemia and its diagnostic tests.

Blood sample taken as part of leukemia testingShare on Pinterest
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Leukemia produces symptoms that also occur with other, unrelated conditions. As a result, people with leukemia might sometimes not recognize the signs right away.

Leukemia can cause:

Other symptoms include:

In order to diagnose leukemia, a doctor will first perform a physical examination. They will look for signs of infection, swelling, and bruising, which can indicate the presence of the condition.

Blood tests are the main method of diagnosing leukemia. A doctor may use other tests in addition to blood tests to confirm the diagnosis or examine disease progression.

Diagnostic tests can include:

Blood tests

Doctors may use several types of blood tests to diagnose leukemia, such as:

  • Complete blood count: This measures the amount of red blood cells, white blood cells, and platelets in the blood.
  • Differential blood test: This measures the different types of white blood cells present in the bloodstream.
  • Peripheral blood smear: This involves smearing a drop of blood across a surface for examination under a microscope to identify cell changes that indicate leukemia.

Flow cytometry

Flow cytometry can help determine the type of leukemia. It involves exposing blood cells to antibodies that attach themselves in different ways depending on whether cancer is present or not.

This test also measures DNA levels in cells, which can indicate the potential speed of cancer growth.


A biopsy can provide additional details about the type of cancer, its growth, and how far it has spread.

In leukemia cases, doctors typically use either bone marrow biopsy or lymph node biopsy.

During bone marrow biopsy, a doctor inserts a long needle into the bone marrow, usually through the hip, and collects a piece of solid or liquid bone marrow for analysis. The procedure does not last long but can be uncomfortable.

Lymph node biopsy involves removing either part or all of a lymph node while a person is under anesthesia. It may be necessary if a lymph node grows following diagnosis, which indicates that the cancer has become more aggressive.

Imaging tests

Imaging tests produce detailed images of the inside of the body and help doctors determine disease progression or the risk of complications.

These tests can include:

  • X-rays: These produce simple images by passing radiation through the body.
  • CT scans: These produce more detailed images of the body.
  • PET scans: These scans highlight location of the cancer around the body using a radioactive substance.
  • MRI scans: This type of scan uses strong magnetic fields and radio waves to produce detailed images of the inside of the body.
  • Ultrasound scans: These use high-frequency sound waves and help determine whether organs or lymph nodes are enlarged.

Pulmonary function tests

Doctors use various pulmonary function tests to assess lung strength before and after treatment. These help doctors decide which treatments are suitable and whether there is a risk of complications.

Pulmonary function tests can include:

  • Spirometry: This test involves breathing into a tube for a computer to measure the amount and speed of exhaled air.
  • Lung plethysmography: In this test, a machine measures inhaled air and the force of exhaled air.
  • Lung diffusion test: During the test, a person breathes in a special gas and holds it for a few seconds before exhaling it into a tube. Doctors use lung diffusion tests to assess how well the lungs are taking in oxygen and expelling carbon dioxide.

Lumbar puncture

A lumbar puncture involves inserting a needle into the lower back and collecting cerebrospinal fluid. The fluid can tell doctors how far leukemia has spread.

There are numerous treatments for leukemia available. Doctors will decide on the most suitable treatment options using the information about the type and severity of leukemia a person has.

Treatment for leukemia can include:

According to the National Cancer Institute (NCI), the 5-year survival rate for all types of leukemia is 65%. This means that around 65% of people will still be alive 5 years after receiving a leukemia diagnosis.

The NCI also notes that mortality rates for leukemia have fallen by almost 2% each year since 2010.

Anyone with symptoms of leukemia should seek guidance from a doctor. The doctor may perform a physical examination and order a blood test.

Individuals in remission from leukemia should contact a doctor if they notice any signs of reoccurrence, such as infection, easy bruising, or bleeding.

Leukemia is a cancer of blood or bone marrow. It typically starts in immature blood cells, which are detectable through blood tests. Doctors may also use other tools when diagnosing leukemia, such as imaging tests or a biopsy.

Doctors use a combination of tests to diagnose leukemia and determine its severity. Anyone experiencing signs of leukemia may need a blood test and should contact a healthcare professional straight away.