Side effects of low white blood cells

White blood cells (WBCs) fight infections from bacteria, viruses, fungi, and other pathogens (organisms that cause infection). One important type of WBC is the neutrophil. These cells are made in the bone marrow and travel in the blood throughout the body. They sense infections, gather at sites of infection, and destroy the pathogens.

Índice Show

Why It Occurs
How Low Is Too Low?
What You Can Do to Prevent Infections
When to Call the Doctor
Alternative Names
Review Date 4/28/2021
What causes a low white blood cell count?
Treating a low white blood cell count
Signs of an infection may include:
Non-urgent advice: See a GP if:
Things you can do yourself to avoid infections
What happens if you have a low count of white blood cells?
Do low white blood cells make you tired?
What is the most common reason for low white blood cell count?
Is low white blood count serious?

When the body has too few neutrophils, the condition is called neutropenia. This makes it harder for the body to fight off pathogens. As a result, the person is more likely to get sick from infections. In general, an adult who has fewer than 1,000 neutrophils in a microliter of blood has neutropenia.

If the neutrophil count is very low, fewer than 500 neutrophils in a microliter of blood, it is called severe neutropenia. When the neutrophil count gets this low, even the bacteria normally living in a person's mouth, skin, and gut can cause serious infections.

Why It Occurs

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 drugs, which slow bone marrow production of healthy WBCs.

How Low Is Too Low?

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.

What You Can Do to Prevent Infections

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.

When to Call the Doctor

If you have any of the following symptoms, call your health care provider:

Fevers, chills, or sweats. These may be signs of infection.
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 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.

Alternative Names

Neutropenia and cancer; Absolute neutrophil count and cancer; ANC and cancer

References

American Cancer Society website. Infections in people with cancer: why people with cancer are more likely to get infections. www.cancer.org/treatment/treatments-and-side-effects/physical-side-effects/infections/infections-in-people-with-cancer.html. Updated March 13, 2020. Accessed July 30 2, 2021.

Centers for Disease Control and Prevention website. Preventing infections in cancer patients. www.cdc.gov/cancer/preventinfections/index.htm. Updated November 10, 2020. Accessed July 30, 2021.

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.

Review Date 4/28/2021

Updated by: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

A low white blood cell count usually means your body is not making enough white blood cells. It can increase your risk of getting infections.

What causes a low white blood cell count?

Common causes include:

cancer treatment, like radiotherapy
antipsychotic medicines
medicine for an overactive thyroid
some cancers, like leukaemia
infections such as HIV or hepatitis
autoimmune disorders, like rheumatoid arthritis

Agranulocytosis and neutropenia are conditions that cause a low white blood cell count.

Treating a low white blood cell count

A blood test can tell you if your white blood cell count is low.

Your treatment will depend on what's causing your condition and will often include antibiotics.

You may also need specific treatment:

to boost your white blood cells
if you've got an infection

Signs of an infection may include:

a high temperature
chills and shivering
sore throat
mouth sores that keep returning
toothache
skin rashes
tiredness
flu-like symptoms

Occasionally, infections can lead to a life-threatening condition called sepsis.

Non-urgent advice: See a GP if:

you know you're at risk of a low white blood cell count and you get an infection
you keep getting infections

Things you can do yourself to avoid infections

If you have a low white blood cell count caused by illness or medicine you should take steps to avoid infections.

What happens if you have a low count of white blood cells?

A low white blood cell count usually means your body is not making enough white blood cells. It can increase your risk of getting infections.

Do low white blood cells make you tired?

Can low white blood cells cause fatigue? Low white bloods cells likely aren't the cause of fatigue. If you have low WBC and are increasingly feeling fatigued, both are likely symptoms of an underlying issue.

What is the most common reason for low white blood cell count?

ANSWER: A low white blood cell count almost always is related to a decrease in a type of infection-fighting white blood cell called neutrophils. When you have a low level of neutrophils, the condition is known as neutropenia. There are many causes of neutropenia, and some medications can lead to this problem.

Is low white blood count serious?

Summary. A low white blood cell count is a consequence of serious diseases, and it can lead to harmful health problems—including infections, slow healing, and cancer. A low white blood cell count doesn't cause symptoms, but the complications of a low white blood cell count can cause many different symptoms.