Low white blood cell count and cancer
A person with cancer can develop a low WBC count from the cancer or from treatment for the cancer. Cancer may be in the bone marrow, causing fewer neutrophils to be made. The WBC count can also go down when cancer is treated with chemotherapy medicines, which slow bone marrow production of healthy WBCs.
When your blood is tested, ask for your WBC count and specifically, your neutrophil count. If your counts are low, do what you can to prevent infections. Know the signs of infection and what to do if you have them.
Prevent infections by taking the following measures:
- Be careful with pets and other animals to avoid catching infections from them.
- Practice safe eating and drinking habits.
- Wash your hands often with soap and water.
- Stay away from people who have symptoms of an infection.
- Avoid traveling and crowded public places.
If you have any of the following symptoms, contact your health care provider:
- Fevers, chills, or sweats.
- Diarrhea that does not go away or is bloody.
- Severe nausea and vomiting.
- Being unable to eat or drink.
- Extreme weakness.
- Redness, swelling, or drainage from any place where you have an IV (intravenous) line inserted into your body.
- A new skin rash or blisters.
- Pain in your stomach area.
- A very bad headache or one that does not go away.
- A cough that is getting worse.
- Trouble breathing when you are at rest or when you are doing simple tasks.
- Burning when you urinate.
American Cancer Society website. Why are people with cancer more likely to get infections. www.cancer.org/cancer/managing-cancer/side-effects/low-blood-counts/infections/why-people-with-cancer-are-at-risk.html. Updated February 13, 2024. Accessed April 8, 2025.
Berliner N. Leukocytosis and leukopenia. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 153.
Centers for Disease Control and Prevention website. Preventing infections in cancer patients. www.cdc.gov/cancer-preventing-infections/. Accessed April 8, 2025.
Freifeld AG, Kaul DR. Infection in the patient with cancer. In: Niederhuber JE, Armitage JO, Kastan MB, Doroshow JH, Tepper JE, eds. Abeloff's Clinical Oncology. 6th ed. Philadelphia, PA: Elsevier; 2020:chap 34.
Reviewed By: Warren Brenner, MD, Oncologist, Lynn Cancer Institute, Boca Raton, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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