White Blood Cells: What Do They Do?

11/16/2021 | 5 min. read

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Our bodies do so much behind the scenes, with most of that work happening on an unconscious level. While we are going about our day-to-day business, our bodies keep us safe, keep us breathing, and keep our blood pumping.

Our blood is impressive all on its own, with each component performing a specific job while also working cohesively to keep the body functional. One of the components, the white blood cells, are a critical part of our immune system.

Healthy Directions has more information about what they do and why they are so important.

White Blood Cell Basics

The blood has four essential components — red blood cells, also called erythrocytes or RBCs, white blood cells, also known as leukocytes or WBCs, plasma, and platelets. As a whole, white blood cells only make up around 1% of the blood but have a much more significant impact.

There are also subcategories of white blood cells, each with its own job.

  • Basophils secrete chemicals like histamine to help trigger and direct the cells of the immune system and responses in the presence of foreign invaders. They occur in the presence of asthma in the body.
  • Eosinophils are most effective at attacking cancer cells and parasites. They are also present with some allergies and allergic disorders, especially those with nasal symptoms like congestion, sneezing, or a runny nose.
  • Lymphocytes, also known as t cells and b cells or t lymphocytes and b lymphocytes, fight against bacteria, viruses, and other severe infections by creating antibodies. This makes them incredibly important, as they remember how to fight all different kinds of diseases to be more effective when it reencounters them.
  • Monocytes have the longest lifespan of all of the white blood cells, and they use that time to help break down and fight against bacteria. Monocytes also help to destroy dead tissue. They are also the largest in size of the WBC types.
  • Neutrophils kill and then digest bacteria and fungi. They are not only the first line of defense against invaders and infectious diseases; they are also the most numerous type of white blood cell in the body. Neutrophils also last less than a single day in the body.

Altogether, the white blood cells are essentially the body’s “immunity” cells. These cells are constantly vigilant, looking for anything that might be harmful.

When they identify a potentially dangerous cell, whether a bacteria, virus, fungi, or allergen, they spring into action and send a rush of WBCs to the area to fight back.

Where Are White Blood Cells Created?

As long as everything functions the way it should, the body can produce and maintain its white blood cells. It does this by “manufacturing” them in the bone marrow, the spongy tissue present inside some bones like the hip and thigh bones. The cells that create them, known as hematopoietic stem cells, also manufacture other blood cells.

Once produced, the white blood cells are stored in lymph tissue when they aren’t floating around in the blood waiting for a target.

If you’ve ever noticed that your lymph nodes are swollen when you’re not feeling well (especially the lymph nodes located around your face), this is directly related to the number of white blood cells that you have in your body at that time.

How Many White Blood Cells Should I Have?

Your white blood cell count can be measured by having a simple blood test ordered by your primary care physician to take a look at your complete blood count. This test is likely to be performed if you are experiencing any signs of illness, like fever, chills, or fatigue, or as part of your annual wellness workup.

Although the normal range varies depending on where your blood test is performed, it is usually from 4,000 to 10,000 mcL, or cells per microliter of blood. However, everyone’s average can vary.

Elevated White Blood Cell Count

An elevated white blood cell count, referred to medically as leukocytosis, is often the result of some sort of infection in the body or a white blood cell disorder.

However, that is not the only reason it happens. Any kind of emotional or physical stress that occurs to the body can trigger an increase in the production of white blood cells. This stress can even include factors like exercise and pregnancy.

In some situations, the body just overproduces white blood cells for no apparent reason, leading to a high WBC count with no biological cause.

Low White Blood Cell Count

Your white blood cell count can also be below the normal range, and this is referred to medically as leukopenia. While this isn’t as common, low WBC counts tend to result from more serious issues occurring in the body.

In addition, when you have fewer white blood cells than you should, your body is also more at risk for developing other infections.

How Can I Help Support My White Blood Cells?

While there isn’t anything you can do to impact your WBC count specifically, you can support your immune system in other ways.

One of the best things you can do for yourself is to pay attention to your sleep hygiene. When your body doesn’t get the sleep it needs, nearly every one of your body systems suffers.

This includes your immune system, as it doesn’t have the power and energy it needs to fight off illness as effectively as before. When you get better, longer sleep, you get the rest you need so that your body can repair and replenish itself overnight.

Your diet also plays a part in supporting your immune system. Drink plenty of water, eat more fresh fruits and vegetables, and consider taking an immune support supplement.


Your white blood cells are always working hard for you, even if you aren’t aware of them. They are constantly on guard, patrolling your body for any signs of invaders, ready to attack.

While you can’t support your white blood cells directly, you can focus on giving your body, and specifically your immune system, what it needs to run smoothly. Healthy Directions is here to help.


What Are White Blood Cells? | University of Rochester Medical Center

White Blood Count (WBC) | MedlinePlus Medical Test

Sleep Hygiene Tips - Sleep and Sleep Disorders | CDC

Healthy Directions Staff Editor