What does it mean when white blood count is high


White blood cells are part of the human body’s immune system, and they play an important role in protecting us from infection and disease. When a person’s white blood count is high, this usually indicates that the body is fighting off an infection or other form of illness. High white blood counts can also be a sign of an underlying medical condition such as cancer, autoimmune disorders, and bone marrow problems. It is important to consult with your doctor if you have high white blood counts so that they can determine the underlying cause and provide effective treatment.

White Blood Cells (WBCs) are essential for fighting infections in the body by producing antibodies that target any foreign substances as well as pathogens like bacteria and viruses. The normal range of WBCs in an adult is 4500-10000 per microliter of blood. High WBC counts above 10000 per microliter indicate an increase in WBC production possibly due to underlying medical conditions or infections such as:

  • Leukemia
  • Tuberculosis
  • Severe bacterial infections
  • Autoimmune disorders such as rheumatoid arthritis and lupus.
  • Additionally, bone marrow diseases such as myelodysplasia can lead to high white blood cell counts due to overactive bone marrow production of these cells.

What is a White Blood Cell Count?

A white blood cell count (WBC) is a test that provides a measure of the number of white blood cells in a volume of blood. White blood cells are a part of the immune system and help to protect the body from infections and diseases. A high white blood cell count can be indicative of an infection, inflammation, or another underlying medical condition.

In this article, we will discuss what a white blood cell count is and what can cause a high white blood cell count:

What is a normal white blood cell count?

White blood cell (WBC) count is a measure of the number of white blood cells per volume in the blood. A normal WBC count is typically between 4,500 and 10,000 cells per microliter (cells/mcL). The range may vary slightly from lab to lab.

The body constantly produces new WBCs to fight infection and disease, and their levels are affected by stress and exhaustion. A high WBC count could mean that an infection or inflammation is present in the body. Other signs might include fever, night sweats, chills, sore throat, fatigue and general feeling of sickness. It can also show other illnesses such as cancer or autoimmune diseases such as lupus or rheumatoid arthritis.

The main types of white blood cells are:

  • Neutrophils (which help defend against bacterial infections)
  • Lymphocytes (which play a role in protection against viruses and leukemia)
  • Monocytes (which are part of the immune system’s scavenger system that helps clear away old red blood cells).

In most cases, if a person has a high WBC count, it could indicate an active infection or inflammation in their body that needs further investigation by a physician.

What is a high white blood cell count?

A high white blood cell count indicates an increased production of white blood cells in your body. White blood cells, or leukocytes, are parts of the immune system and are responsible for protecting the body from infections and illnesses. High white blood cell counts usually suggest that you may have an infection or inflammation somewhere in your body, however it can also be caused by other conditions such as a reaction to a medicine or cancer.

To determine if you have a high white blood cell count (leukocytosis), your doctor will make use of a complete blood count (CBC). The CBC will give your doctor an overview of the types and number of cells in your bloodstream, including red blood cells, platelets, hemoglobin and hematocrit levels. Your individually categorized white cell types—which include neutrophils, lymphocytes and monocytes—will also be taken into account to determine if you have abnormally large amounts of any type.

If your doctor finds that you have abnormally high levels (over 10 x 10^9/L) then they can run additional tests to identify the reason behind it. Depending on the underlying cause further treatment may be necessary to reduce the level back down to normal levels.

Causes of High White Blood Cell Count

Having an elevated white blood cell count can be a sign of an underlying health issue. Generally, causes of high white blood cell count can range from mild infections to more serious illnesses. It is important to consult with a doctor to determine the underlying cause.

In this article, we will look at some of the possible causes of high white blood cell count:


One of the primary causes of a high white blood cell count is an infection. This could be a bacterial, viral or fungal infection. An increased white blood cell count is an indication that your body is trying to fight off the foreign invader.

When your body is fighting off a viral infection, such as the flu, your doctor may recommend a blood test to see if have an elevated white blood cell count. If so, it’s likely they will start you on an antiviral medication. However, if you have a bacterial infection such as strep throat or sinusitis, they may prefer antibiotic treatment in addition to or instead of antiviral medications.

Certain fungal infections can also cause your body to produce more white blood cells than normal in order to fight it off. If this occurs, the doctor may order additional testing – such as cultures and microscopic examination – to identify which type of fungus is causing the infection, so they can determine the most effective treatment plan that should include some kind of antifungal medication.


High white blood cell count can be caused by a wide variety of medical conditions, from mild to serious, and is indicative of inflammation or infection in the body. Inflammation is a response mechanism of the human body to injury or infection, induces fever and activates immune cells to fight off foreign invaders. During this process neutrophils, monocytes and lymphocytes are released into the blood, leading to an increase in white blood cells (WBC) count.

Other causes of high WBC count include autoimmune disorders where the immune system attacks the body’s own organs or tissues without reason. Certain cancers such as leukemia can cause elevated white blood cell levels too.

It is important to consult your healthcare provider if you experience any symptoms that point towards high WBC count such as fever, fatigue and rapid heart rate so tests can be carried out for proper diagnosis and treatment.


High levels of stress can cause an increase in white blood cell count. Stress triggers the body to release hormones like cortisol and adrenaline, which signals the immune system to produce more white blood cells. This is because when our bodies are under stress, they think that it is under attack and need more tools to fight off potential illnesses or allergies.

High levels of stress for an extended period of time can lead to a situation where your body is constantly working squandering resources, thus resulting in a higher white blood cell count for long-term stress.

Stressful situations or events that could contribute to this include:

  • being pessimistic
  • worrying
  • job burnout
  • losing a loved one

Certain Medications

Certain medications may increase white blood cell count and should be monitored closely by a doctor. These include corticosteroids, some heart medications, and certain cancer treatments such as chemotherapy.

  • Corticosteroids are powerful anti-inflammatory drugs used to treat a wide variety of conditions. They can cause an increase in the production of white blood cells as one of their side effects.
  • Heart medications, such as calcium channel blockers, can also increase white blood cell production, but this is rarely seen in clinical practice.
  • Chemotherapy drugs used to treat cancer can also cause leukocytosis (an increase in the number of circulating white blood cells). This is usually temporary, however it can be dangerous if not monitored closely by a doctor.


Leukemia is a type of cancer that originates in the bone marrow, where new blood cells are created. White blood cells, which are responsible for fighting infections, can start overproducing, creating too many immature white cells, or blasts. The disease is further classified by how quickly it progresses from acute to chronic stages.

Acute leukemia can progress faster than chronic and is most often seen in children, although it occur in adults as well. Chronic leukemia progresses more slowly and tends to be a bit less aggressive than acute leukemia; however, it’s more common in adults and may present for years before diagnosis.

Symptoms of high white blood cell count due to leukemia include:

  • Fatigue and weakness from anemia
  • Frequent infections from neutropenia (too few infection-fighting white cells)
  • Easy bruising or bleeding due to thrombocytopenia (low platelet count)
  • Other symptoms may include night sweats and fever with swollen glands due to enlargement of the spleen or liver (hepatosplenomegaly) caused by an overproduction of immature cells in the bone marrow.

Treatment typically involves chemotherapy or radiation therapy; stem cell transplants may also be necessary.

Other Diseases

Various illnesses and conditions can lead to a high white blood cell count. Certain viruses, such as the flu or the Epstein-Barr virus, can increase your white blood cell count, causing it to rise enough to be detectable on a routine lab test. However, when tested further, patients usually have a normal amount of each type of white blood cell involved in fighting infection.

Autoimmune diseases such as lupus and rheumatoid arthritis can also cause an elevated white blood cell count. Patients with these conditions have an overactive immune system that puts their bodies into an inflammatory “fight mode” and causes the production of extra white blood cells.

Certain chronic infections (such as HIV) and cancers like lymphoma or leukemia can trigger elevations in the number of certain types of white blood cells in some cases. In addition, reoccurring stress or trauma—like that caused by surgery—may temporarily elevate levels.

Other diseases may cause persistent high levels of neutrophils (a type of white blood cell). These include bacterial infections like tuberculosis or chronic pulmonary disease and various genetic disorders that occur more commonly in different ethnic populations like sickle cell anemia or thalassemia (a disorder affecting hemoglobin production).

Diagnosis and Treatment

When a person’s white blood cell count is high, it could indicate that their body is battling an infection or disease. This can occur due to a bacterial, viral or other type of infection, and the levels may vary, depending on the severity of the condition. If a high white blood count is detected, it is important to identify the underlying cause in order to effectively treat it.

Let’s explore diagnosis and treatment options:


To diagnose the reason for a high white blood cell count, a doctor may order tests to determine whether a patient has an infection or some other underlying condition. A complete blood count (CBC) test is done to measure different types of cells in the blood, including white blood cells. This test can also indicate if there is anemia, an indication of low red blood cell count, or other abnormalities in the shape, size and number of red and white cells.

Additional tests may be necessary to determine additional information and parameters related to white blood cell count:

  • A differential white cell count is performed on individual types of lymphocytes, monocytes or granulocytes (eosinophils, basophils and neutrophils).
  • An immunology panel might include tests to check for antinuclear antibodies (ANA), rheumatoid factor (RF), immune complexes, complement proteins and immunoglobulins.
  • A chest X-ray is required to confirm if there is an infection in the lungs.
  • A liver function test can show elevated levels of liver enzymes if patients have any liver problems that could be causing a high WBC count.
  • Urine testing may reveal if there are any signs of an infection that could be causing a rise in WBCs.
  • Blood cultures are conducted when testing for bacterial infections such as sepsis that cause high white blood cell counts or fever. Other cultures might look for fungal infections that can lead to leukocytosis (high WBC).
  • In some cases, imaging studies such as CT scans can help with diagnosis by providing clear images which allow doctors to see abnormalities that may help pinpoint the source of abnormally high WBCs such as tumors or abscesses in internal organs.


Treatment for high white blood cell count will depend upon the underlying cause. Your doctor may suggest simple steps like getting more rest, eating a healthier diet, and reducing stress and anxiety. Antibiotics may be prescribed for infections that are increasing white blood cells.

For chronic conditions such as an autoimmune disorder or cancer, your doctor may prescribe medications to control and reduce the elevated white blood cell count; these could include corticosteroids such chemotherapy drugs or monoclonal antibodies. In some cases two or more medications in combination might be prescribed to manage the condition better.

In extreme cases, treatment including radiation therapy or stem cell transplants may be recommended to reduce white blood cells and prevent further complications. Surgery is rarely required but might be recommended in cases where a tumor is causing an increase in WBCs. In this case, removal of the tumor along with chemotherapy would be prescribed by your doctor to lower your white blood cell count if other treatments have been ineffective.


In conclusion, a high white blood cell count is not necessarily a cause for concern. It may be due to the body’s natural response to environmental elements such as stress, exercise, or illness. However, high white blood cell count can also indicate the presence of an infection, chronic disease, or even cancer.

If any of these symptoms coincide with a high white blood cell count it is important to visit your doctor to investigate further and make sure you are healthy. Only then will you know for sure what caused your high white blood cell count and you can receive the proper treatment plan for whatever condition is present.