What is the WBC (white blood cell) count

A white blood cell (WBC) count is a test that measures the number of white blood cells in your body. This test is often included with a complete blood count (CBC). The term “white blood cell count” is also used more generally to refer to the number of white blood cells in your body.

There are several types of white blood cells, and your blood usually contains a percentage of each type. Sometimes, however, your white blood cell count can fall or rise out of the healthy range.

Purpose of a WBC count

Having a higher or lower number of WBCs than normal may indicate an underlying condition.

A WBC count can detect hidden infections within your body and alert doctors to undiagnosed medical conditions, such as autoimmune diseases, immune deficiencies, and blood disorders.

This test also helps doctors monitor the effectiveness of chemotherapy or radiation treatment in people with cancer.

Types of WBCs

WBCs, also called leukocytes, are an important part of the immune system. These cells help fight infections by attacking bacteria, viruses, and germs that invade the body.

White blood cells originate in the bone marrow but circulate throughout the bloodstream. There are several different types of white blood cells, each with varying responsibilities:

• Lymphocytes: These are vital for producing antibodies that help the body to defend itself against bacteria, viruses, and other threats.
• Neutrophils: These are powerful white blood cells that destroy bacteria and fungi.
• Basophils: These alert the body to infections by secreting chemicals into the bloodstream, mostly to combat allergies.
• Eosinophils: These are responsible for destroying parasites and cancer cells, and they are part of an allergic response
• Monocytes: These are responsible for attacking and breaking down germs or bacteria that enter the body.

A normal WBC count

Infants are often born with much higher numbers of WBCs, which gradually even out as they age.

According to the University of Rochester Medical Center (UMRC), these are the normal ranges of WBCs per microliter of blood (mcL):

Age range                                  WBC count (per mcL of blood)

newborns                                             9,000 to 30,000

children under 2                               6,200 to 17,000

children over 2 and adults            5,000 to 10,000

These normal ranges can vary by lab. Another common measurement for the volume of blood is cubic millimetre or mm3. A microliter and cubic millimetre equal the same amount.

The types of cells that make up WBCs usually fall within a normal percentage of your overall WBC count.

The normal percentages of the types of WBCs in your overall count are usually in these ranges, according to the Leukemia & Lymphoma Society (LLS):

Type of WBC      Normal percentage of overall WBC count

Neutrophil           55 to 73 per cent

Lymphocyte        20 to 40 per cent

Eosinophil           1 to 4 per cent

Monocyte           2 to 8 per cent

Basophil               0.5 to 1 per cent

Higher or lower numbers of WBCs than normal can be a sign of an underlying condition.

Having a higher or lower percentage of a certain type of WBC can also be a sign of an underlying condition.

If levels of one particular type of white blood cell increase, this may be due to a specific trigger.

• Monocytes: High levels of monocytes may indicate the presence of chronic infection, an autoimmune or blood disorder, cancer, or other medical conditions.
• Lymphocytes: If there is an elevation in the level of lymphocytes, the condition is known as lymphocytic leukocytosis. This may occur as a result of a virus or an infection, such as tuberculosis. It may also be linked to specific lymphomas and leukaemias.
• Neutrophils: Increased levels of neutrophils in their body lead to a physical state known as neutrophilic leukocytosis. This condition is a normal immune response to an event, such as infection, injury, inflammation, some medications, and certain types of leukaemia.
• Basophils: Rising levels of basophils may occur in people with a history of underactive thyroid disease, known as hypothyroidism, or as a result of certain other medical conditions.
• Eosinophils: If a person registers high levels of eosinophils, the body might be reacting to a parasitic infection, allergen, or asthma.

Symptoms of an abnormal WBC count

The symptoms of a low WBC count include:

body aches

fever

chills

headaches

High WBC counts don’t often cause symptoms, although the underlying conditions causing the high count may cause their own symptoms.

The symptoms of a low WBC count may prompt your doctor to recommend a WBC count. It’s also normal for doctors to order a CBC and check your WBC count during an annual physical examination.

What to expect from a WBC count

A healthcare provider or lab technician needs to draw blood to check your WBC count. This blood sample is taken either from a vein in your arm or a vein on the back of your hand. It only takes a couple of minutes to draw your blood, and you may experience minor discomfort.

The healthcare provider first cleans the needle site to kill any germs and then ties an elastic band around the upper section of your arm. This elastic band helps the blood fill your vein, making it easier for the blood to be drawn.

The healthcare provider slowly inserts a needle into your arm or hand and collects the blood in an attached tube. The provider then removes the elastic band from around your arm and slowly removes the needle. Finally, the technician applies gauze to the needle site to stop the bleeding.

Healthcare providers use a different technique when drawing blood from young children and infants: Providers first puncture the skin with a lancet (a pricking needle), and then use a test strip or a small vial to collect the blood.

Results are sent to a lab for review.

Complications from a WBC count

Having your blood drawn is a simple procedure, and complications are extremely rare.

It can be difficult to take blood from people with small veins. The lab technician may be unable to locate a vein, or once the needle is inside the arm or hand, they may have to move the needle around in order to draw blood. This can cause a sharp pain or a stinging sensation.

Rare complications include:

infection at the needle site

excessive bleeding

lightheadedness or fainting

bleeding underneath the skin (hematoma)

How to prepare for a WBC count

A WBC count requires no specific preparation. You simply schedule an appointment with your doctor or set up an appointment at a local medical laboratory.

Certain medications can interfere with your lab results and either lower or increase your WBC count. The drugs that may affect your test results include:

corticosteroids

quinidine

heparin

clozapine

antibiotics

antihistamines

diuretics

anticonvulsants

sulfonamides

chemotherapy medication

Prior to having your blood drawn, tell your doctor about all prescription and nonprescription medications that you’re currently taking.

Understanding the results of a WBC count

Abnormal test results are classified by numbers that are higher or lower than the normal range for your age.

A low or high WBC count can point to a blood disorder or other medical condition. To identify the exact cause of a high or low WBC count, your doctor will take several factors into consideration, such as your list of current medications, symptoms, and medical history.

Leukopenia is the medical term used to describe a low WBC count. A low number can be triggered by:

HIV

autoimmune disorders

bone marrow disorders or damage

lymphoma

severe infections

liver and spleen diseases

lupus

radiation therapy

some medications, such as antibiotics

Leukocytosis is the medical term used to describe a high WBC count. This can be triggered by:

smoking

infections such as tuberculosis

tumours in the bone marrow

leukaemia

inflammatory conditions, such as arthritis and bowel disease

stress

exercise

tissue damage

pregnancy

allergies

asthma

some medications, such as corticosteroids

After diagnosing the cause of a high or low WBC count and recommending a treatment plan, your doctor will periodically recheck your WBCs.

If your WBC count remains high or low, this can indicate that your condition has worsened. Your doctor may adjust your treatment.

If your WBC count shows a normal range, this usually indicates that the treatment is working.

Q&A: Increasing your WBC count

Q:

Are there any foods I can eat that will help increase my WBC count?

A:

No specific foods or diet is proven through research to increase the production of white blood cells.

It’s important to include a good source of protein in your diet, as amino acids found in protein, are needed to build WBCs.

Vitamins B-12 and folate are also needed to produce WBCs, so consider adding a multivitamin and mineral supplement daily. Though not proven, some believe that adding vitamin C, vitamin E, zinc, garlic, selenium, and even spicy foods to your diet can boost the immune system.

If you’re being treated for cancer or other causes of leukocytosis, talk to your doctor before taking any supplements, as they might interfere with treatments.

Deborah Weatherspoon, PhD, RN, CRNA
https://www.healthline.com/

https://www.medicalnewstoday.com/articles/315133.php#high-levels