Low White Blood Cell Count


What are white blood cells?

White blood cells are created in bone marrow and are a part of the immune system. White blood cells help the body identify and fight a variety of diseases and infections. The human body produces about 100 billion white blood cells each day.

There are five major types of white blood cells:

  • Basophils
  • Eosinophils
  • Lymphocytes
  • Neutrophils
  • Monocytes

Who is likely to have a low white blood cell count?

A low white blood cell count can occur in anyone. The number of white blood cells in the body can vary, depending on a person’s age, race, and gender, and if he or she has certain medical conditions.

People who are undergoing certain treatments for cancer are likely to have a low white blood cell count.

Possible Causes

What causes a low white blood cell count?

If a person has too many—or too few—white blood cells in the body, it may mean that there is a disorder of some kind. A white blood cell count of less than 4,000 cells per microliter of blood is considered low. Sometimes a low white blood cell count is something you are born with (a genetic condition), which may or may not be a cause for concern. A low white blood cell count is associated with certain conditions, including:

  • Cancer (caused by chemotherapy treatments)
  • Bone marrow disorders or damage
  • Autoimmune disorders (problems with the immune system in which the body attacks itself), such as lupus
  • Infections (including tuberculosis and HIV)
  • Immune system conditions
  • Crohn’s disease
  • Malnutrition
  • Radiation treatments for cancer
  • Rheumatoid arthritis
  • Vitamin deficiencies
  • Liver damage and/or enlarged spleen

Care and Treatment

How is a low white blood cell count diagnosed?

To determine if a person has a low white blood cell count, the doctor will order a blood test known as a complete blood count. The doctor may order a complete blood count test on a regular basis to check on a patient who has certain conditions, such as an infection or immune system disorder. Other information from the complete blood count will help your doctor come up with a list of possible diagnoses. Your doctor may recommend a referral to a hematology specialist.

What can I do to avoid/prevent a low white blood cell count?

To minimize the chances of certain diseases and a low white blood cell count:

  • Practice good hygiene. For instance, wash your hands after using the bathroom and before cooking.
  • Be careful around pets and other animals that might transmit infections.
  • Make sure foods are thoroughly cooked before eating them.
  • Stay away from people who have infections.
  • Practice safe sex; avoid drugs and sharing needles.

When to Call the Doctor

When should I see a doctor about a possible low white blood cell count?

Ask your doctor if he or she is concerned about your white blood cell count and if you will need additional tests. If your white blood cell count is low, and you feel like you have an infection, contact your healthcare provider right away.

Last reviewed by a Cleveland Clinic medical professional on 01/12/2018.


  • American Association for Clinical Chemistry. White Blood Cell Count. (https://labtestsonline.org/understanding/analytes/wbc/tab/test/) Accessed 2/26/2018.
  • Merck Manual. Overview of White Blood Cell Disorders. (https://www.merckmanuals.com/home/blood-disorders/white-blood-cell-disorders/overview-of-white-blood-cell-disorders) Accessed 2/26/2018.
  • National Cancer Institute. White blood cell. (https://www.cancer.gov/publications/dictionaries/cancer-terms?cdrid=45993) Accessed 2/26/2018.

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