High or Low White Blood Cell Counts Can Lead to Health Problems (2022)

White blood cells (WBCs) are a part of the immune system. They help fight infection and defend the body against other foreign materials.

Different types of white blood cells have different jobs. Some are involved in recognizing intruders. Some kill harmful bacteria. Others make antibodies to protect your body against exposure to bacteria and viruses.

This article discusses the different types of white blood cells and their various functions.

Types of WBC

White blood cells are are also known as leukocytes. They are the body's defense against infections. There are several different types with different purposes.

Some of the cells are part of our innate immune system, meaning they know from birth to attack foreigners. Others are part of our humoral or learned immune system. Humoral immune cells manufacture antibodies after exposure to a germ. This way, the body can be prepared for another attack by that germ.


Neutrophils make up roughly half of the white blood cell population. They are usually the first cells of the immune system to respond to invaders such as bacteria or viruses.

As first responders, they also send out signals alerting other cells in the immune system to come to the scene.

Neutrophils are the main cells found in pus. Once released from the bone marrow, these cells live for only around eight hours. Your body produces roughly 100 billion of these cells every day.


Eosinophils also play a role in fighting off bacteria. They are very important in responding to parasitic infections (such as worms) as well.

They are perhaps best known for their role in triggering allergy symptoms. Eosinophils can go overboard in mounting an immune response against something harmless. For example, eosinophils mistake pollen for a foreign invader.

Eosinophils account for no more than 5% of the white blood cells in your bloodstream. However, there are high concentrations of eosinophils in the digestive tract.


Basophils account for only around 1% of white blood cells. These cells are perhaps best known for their role in asthma. However, they are important in mounting a non-specific immune response to pathogens, organisms that can cause disease.

When stimulated, these cells release histamine, among other chemicals. This can result in inflammation and narrowing of the airways.

Lymphocytes(B and T)

Lymphocytes are also essential in the immune system. They come in two forms: B cells and T cells. Unlike other white blood cells that provide non-specific immunity, B and T cells have specific purposes.

B lymphocytes (B cells) are responsible for humoral immunity, which is the immune response that involves antibodies. B cells produce the antibodies that "remember" an infection. They stand ready in case your body is exposed to that pathogen again.

T cells recognize specific foreign invaders and are responsible for directly killing them. "Memory" T cells also remember an invader after an infection and respond quickly if it is seen again.

B lymphocytes play a key role in the effectiveness of many current vaccines. In some cases, such as tuberculosis and pertussis vaccines, T lymphocytes are the main players.


Monocytes are the garbage trucks of the immune system. Around 5% to 12% of white blood cells in your bloodstream are monocytes. Their most important function is to clean up dead cells in the body.


Leukocytes, better known as white blood cells, take on different forms that perform different roles in the immune system. These include:

  • Neutrophils are the first responder of immune cells.
  • Basophils release histamine to mount a non-specific immune response.
  • Eosinophils fight bacteria and parasites but also provoke allergy symptoms.
  • Lymphocytes are B and T cells that defend against specific invaders.
  • Monocytes clean up dead cells.
(Video) High White Blood Cell Count?? Possible Causes

How WBCs Are Formed

White blood cells begin in the bone marrow in a process called hematopoiesis. All blood cells descend from a common hematopoietic stem cell (HSC). This is also called a "pluripotent" stem cell. These stem cells differentiate—or specialize—in different stages.

The HSC cell first separates into either a lymphoid or myeloid stem cell.

The lymphoid stem cell gives rise to the lymphoid cell line. This is the family of cells that produces B cells and T cells.

The myeloid stem cells give rise to cells called myeloblasts. These further evolve into macrophages, monocytes, neutrophils, basophils, and eosinophils. Myeloblasts can also turn into red blood cells and platelets.

Lab Values

A normal white blood cell count is usually between 4,000 and 10,000 cells per microliter (mcL).

Elevated White Blood Cell Counts

Infections usually cause an elevated white blood cell count, but there are also other possible causes. WBC counts can be increased by overproduction. In other words, the body may release white blood cells early from the bone marrow.

Stress of any form can result in this release of white blood cells. Some causes of an increased white blood cell count include:

  • Infections
  • Cancers such as leukemias, lymphomas, and myelomas, in which a greater number of white blood cells are manufactured
  • Inflammation, such as inflammatory bowel disease and autoimmune disorders
  • Trauma, ranging from fractures to emotional stress
  • Pregnancy
  • Asthma and allergies
  • Exercise

In severe infections, immature white blood cells called blasts may be present. Blasts often appear when the body attempts to get white blood cells on the scene quickly.

Low White Blood Cell Counts

Conditions that may result in a low white blood cellcount include:

  • Severe infections
  • Bone marrow damage or disorders including aplastic anemia, bone marrow "takeover" by blood cancers or metastatic cancer, or drug or chemical-related damage to the bone marrow
  • Autoimmune diseases such as lupus
  • Splenic "sequestration," where white blood cells are accumulated in the spleen.


On its own, a low WBC count doesn't have symptoms. But a low count will often lead to an infection, because not enough white cells are present to fight off the invader. Symptoms of infection may include:

  • Fever
  • Cough
  • Painful or frequent urination
  • Blood in the stools
  • Diarrhea
  • Redness, swelling, or warmth in a region of infection


One of chemotherapy's most common and dangerous side effects is its effect on white blood cells known as neutrophils. Recall that neutrophils are the first responders of our immune system.

A decrease in neutrophils during chemotherapy, known as chemotherapy-inducedneutropenia, increases the risk of serious infection.

Neutropenia makes it more difficult for the body to fight off infections. As a result, bacteria that are normally not very harmful can cause serious illness.


White blood cells are an important part of our immune system. Different types of white blood cells perform different functions in the body. Overall, white blood cells help to protect us against bacteria, viruses, and parasites.

A high white blood cell count is usually a sign of an infection or illness. A low white blood cell count can indicate another type of problem. Low white blood cell counts can leave you vulnerable to serious infections. Chemotherapy is a common cause of low white blood cell counts.

(Video) What Does a Low White Blood Cell Count Mean?

Frequently Asked Questions

  • What is the normal range of white blood cells?

    The normal range (total) of white blood cells is between 4,000 and 10,000 cells per microliter (mcL).

  • What causes a high number of lymphocytes?

    A high number of lymphocytes (lymphocytosis) can be caused by the body's immune system fighting against infection. In these cases, the elevated number of lymphocytes is temporary. However, lymphocytosis can also be caused by several underlying medical conditions, including leukemia.

  • How many types of white blood cells are there?

    There are five types of white blood cells (leukocytes):

    • Neutrophils
    • Lymphocytes (B and T)
    • Monocytes
    • Basophils
    • Eosinophils
  • What does a high WBC mean?

    A high white blood count (WBC) can be a symptom of an underlying disorder. Disorders that are related to a high WBC include autoimmune or inflammatory disease, bacterial or viral infection, leukemia, Hodgkin's disease, or allergic reaction.

  • What are the symptoms of eosinophilia?

    (Video) What happen if white blood cells are high?

    Eosinophilia symptoms can include fever, night sweats, fatigue, and weight loss. This condition is caused by the body producing an excessive number of eosinophils, a type of leukocyte (white blood cell).

  • Where are white blood cells made?

    White blood cells are made in the bone marrow.

13 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

  1. Mayadas TN, Cullere X, Lowell CA. The multifaceted functions of neutrophils. Annu Rev Pathol. 2014;9:181-218. doi:10.1146/annurev-pathol-020712-164023

  2. Mcbrien CN, Menzies-Gow A. The biology of eosinophils and their role in asthma. Front Med (Lausanne). 2017;4:93. doi:10.3389/fmed.2017.00093

  3. Cromheecke JL, Nguyen KT, Huston DP. Emerging role of human basophil biology in health and disease. Curr Allergy Asthma Rep. 2014;14(1):408. doi:10.1007/s11882-013-0408-2

  4. Hoffman W, Lakkis FG, Chalasani G. B cells, antibodies, and more. Clin J Am Soc Nephrol. 2016;11(1):137-54. doi:10.2215/CJN.09430915

  5. Karlmark KR, Tacke F, Dunay IR. Monocytes in health and disease - Minireview. Eur J Microbiol Immunol (Bp). 2012;2(2):97-102. doi:10.1556/EuJMI.2.2012.2.1

  6. Görgens A, Radtke S, Horn PA, Giebel B. New relationships of human hematopoietic lineages facilitate detection of multipotent hematopoietic stem and progenitor cells.Cell Cycle. 2013;12(22):3478-82. doi:10.4161/cc.26900

  7. Hong JW, Noh JH, Kim DJ. Association between White Blood Cell Counts within Normal Range and Hemoglobin A1c in a Korean Population. Endocrinol Metab (Seoul). 2018;33(1):79-87. doi:10.3803/EnM.2018.33.1.79

  8. Riley LK, Rupert J. Evaluation of patients with leukocytosis. Am Fam Physician. 2015;92(11):1004-11.

  9. Flores-Mireles AL, Walker JN, Caparon M, Hultgren SJ. Urinary tract infections: epidemiology, mechanisms of infection and treatment options. Nat Rev Microbiol. 2015;13(5):269-84. doi:10.1038/nrmicro3432

  10. Kasi PM, Grothey A. Chemotherapy-induced neutropenia as a prognostic and predictive marker of outcomes in solid-tumor patients. Drugs. 2018;78(7):737-745. doi:10.1007/s40265-018-0909-3

  11. Cleveland Clinic. Lymphocytosis.

  12. MedlinePlus. White blood count (WBC).

  13. Kanuru S, Sapra A. Eosinophilia. StatPearls.

    (Video) Disorders of Leukocytes/White Blood Cells - An Overview

Additional Reading

(Video) What causes low white blood cell count and what can you do about it? | Masterjohn Q&A Files #01


What is the problem with low white blood cell count? ›

A low white blood cell count in adults is less than 4,000 cells per microliter of blood. A low white blood cell count can be an indicator of certain conditions, including lupus, rheumatoid arthritis, vitamin deficiencies, or a side effect of cancer treatment.

What conditions may be associated with high or low white blood cells? ›

Produced in your bone marrow, they defend your body against infections and disease. But, when there are too many white blood cells, it usually means you have infection or inflammation in your body. Less commonly, a high white blood cell count could indicate certain blood cancers or bone marrow disorders.

Does low white blood cell count mean highest risk for infection? ›

WBCs help the body fight infection and disease. When WBC counts are low, there is a higher risk of infection.

What might be a cause of a high white blood cell count in a patient? ›

A high white blood cell count usually indicates: An increased production of white blood cells to fight an infection. A reaction to a drug that increases white blood cell production. A disease of bone marrow, causing abnormally high production of white blood cells.

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

A low white blood cell count usually is caused by: Viral infections that temporarily disrupt the work of bone marrow. Certain disorders present at birth (congenital) that involve diminished bone marrow function. Cancer or other diseases that damage bone marrow.

Can 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.

How do you improve white blood cells? ›

You can take care of your white blood cells by:
  1. Practicing good hygiene to prevent infection.
  2. Taking vitamins to boost your immune system.
  3. Treating medical conditions where white blood cell disorders are a side effect.
Jul 23, 2021

What are the symptoms of high white blood cell count? ›

Symptoms of a High White Blood Cell Count
  • Fever.
  • Fatigue.
  • Decreased appetite.
  • Sweats.
  • Chills.
  • Swelling of an area of infection.
  • Joint swelling due to infection or autoimmune disease.
  • Itching, with or without a rash.
Mar 31, 2022

Can anxiety cause low white cell count? ›

Calabrese says. In addition, stress decreases the body's lymphocytes — the white blood cells that help fight off infection. The lower your lymphocyte level, the more at risk you are for viruses, including the common cold and cold sores.

Does exercise increase white blood cells? ›

Exercise causes change in antibodies and white blood cells (WBC). WBCs are the body's immune system cells that fight disease. These antibodies or WBCs circulate more rapidly, so they could detect illnesses earlier than they might have before.

Does milk increase white blood cells? ›

Conclusion: Both milks were equally effective to exert favorable effects on the number of the bone marrow cells and the functions of the blood and peritoneal cells involved in immune response. However, only human milk normalized the number of leukocytes and increased the number of neutrophils in peripheral blood.

What can you eat to lower your white blood cell count? ›

To lower your high white blood cell count, you should include the following in your diet: Vitamin C. Eating Vitamin C will help regulate the levels of white blood cells in your body. Fruits like lemons, oranges, and lime are rich in vitamin C, and so are papayas, berries, guavas, and pineapples.

When is white blood count too high? ›

A normal white blood cell count is generally about 4,500 to 11,000/μL. White blood cell counts that are too high or too low may be dangerous, depending on the cause. A high white blood cell count is called leukocytosis, which is generally diagnosed when white blood cell levels exceed 11,000/μL.

What treatment if white blood cells are high? ›

Leukapheresis is a way of removing abnormal white blood cells from the blood. You might have this treatment if you have a very high white blood cell count. Very high numbers of leukaemia cells in the blood can cause problems with normal circulation.

What cancers cause low white blood cell count? ›

Low white blood cell count.

Some cancer treatments, mainly chemotherapy, may lower your body's white blood cells. Cancers that affect the blood and bone marrow can also lower the count. These types of cancers include leukemia, lymphoma, and multiple myeloma.

What is the name for low white blood cell count? ›

Definition. A low white blood cell count (leukopenia) is a decrease in disease-fighting cells (leukocytes) in your blood. Leukopenia is almost always related to a decrease in a certain type of white blood cell (neutrophil). The definition of low white blood cell count varies from one medical practice to another.

When should I be worried about low white blood cells? ›

How many white blood cells (WBCs) someone has varies, but the normal range is usually between 4,000 and 11,000 per microliter of blood. A blood test that shows a WBC count of less than 4,000 per microliter (some labs say less than 4,500) could mean your body may not be able to fight infection the way it should.

How can I raise my white blood cells fast? ›

Lean meats, such as fish, eggs seafood, and skinless poultry contain high quantities of protein. Great plant based sources include lentils, beans and soy. Zinc is one of the best foods to increase white blood cells you can consume as it can help the body produce more WBCs and makes existing WBCs more aggressive.

What cancers cause low white blood cell count? ›

Low white blood cell count.

Some cancer treatments, mainly chemotherapy, may lower your body's white blood cells. Cancers that affect the blood and bone marrow can also lower the count. These types of cancers include leukemia, lymphoma, and multiple myeloma.


1. How Stress Affects Your White Blood Cells (WBCs) and Immune System
(Dr. Eric Berg DC)
2. Why My White Blood Cell Count (WBC) Is Low?
(Dr. Chen's Medical Videos)
3. My white blood count is low: Should I Worry?
(Fox News)
4. Is low white blood cells a sign of cancer?
(Ask About HEALTH)
5. Low White Blood Cell Count |Symptoms |Causes |
(Stream laboratory)
6. How To Raise Or Lower White Blood Cell Count?

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