White Blood Cell Count

What it is

Your white blood cell (WBC) count, also known as the leukocyte count, is a measure of the number of white blood cells in your blood. White blood cells are a vital part of your immune system, acting as the body's defence against infection and disease. They are produced in the bone marrow and circulate in your blood and lymph fluid. There are several different types of white blood cells, each with its own specific role in fighting off invaders like bacteria, viruses, and other harmful substances. The total white blood cell count gives an overall picture of your immune system's activity.

The typical reference range for white blood cells in adults is generally between 4 and 10 x 10^9/l (that's 4 to 10 billion cells per litre of blood). However, these ranges can vary slightly between different laboratories, so it's always best to refer to the specific range provided on your blood test report.

Why it matters

The white blood cell count is a key indicator of your body's health. An elevated count often suggests that your immune system is actively fighting something, such as an infection or inflammation. Conversely, a low count can indicate that your immune system may be compromised, making you more susceptible to infections. Monitoring your white blood cell count can help healthcare professionals assess the effectiveness of treatments, diagnose various conditions, and track the progression of certain diseases. It's a fundamental part of a Full Blood Count (FBC), which provides a broad overview of your blood health.

What can cause it to be high or low

High White Blood Cell Count (Leukocytosis):

A count higher than the typical reference range can be associated with a number of situations. The most common reason is your body fighting off an infection, whether it's bacterial, viral, or fungal. Inflammation, which can be caused by injuries, chronic conditions like arthritis, or even stress, can also lead to an increase in WBCs. Certain medications, such as corticosteroids, can also temporarily raise your WBC count. In some cases, a high count might be associated with more serious conditions affecting the bone marrow, like leukaemia or other blood cancers, or other conditions like tissue damage from a heart attack or severe burns.

Low White Blood Cell Count (Leukopenia):

A count lower than the typical reference range can be associated with various factors. Certain infections, particularly severe viral infections, can sometimes suppress bone marrow function. Some medications, including chemotherapy drugs used to treat cancer, antibiotics, and certain psychiatric medications, can lower WBC counts. Autoimmune diseases, where the immune system mistakenly attacks the body's own tissues, can also lead to a reduced number of white blood cells. Conditions affecting the bone marrow, such as aplastic anaemia or myelodysplastic syndromes, can impair the production of white blood cells. Severe deficiencies in certain vitamins, like B12 or folate, can also play a role.

Lifestyle factors that may help

Maintaining a healthy lifestyle can support your immune system and, by extension, your white blood cell levels. A balanced diet rich in fruits, vegetables, and whole grains provides essential vitamins and minerals that are crucial for immune function. Regular, moderate exercise is also beneficial for overall health and can help to regulate the immune system. Getting enough quality sleep is vital, as sleep deprivation can negatively impact immune responses. Managing stress through techniques like mindfulness, yoga, or spending time in nature can also contribute to a well-functioning immune system. Avoiding smoking and limiting alcohol intake are also important steps for supporting your body's natural defences. These lifestyle choices can contribute to a robust immune system, which may be reflected in healthy white blood cell levels.

Questions to discuss with your GP

• What does my specific white blood cell count mean in the context of my overall health?
• Are there any specific types of white blood cells that are particularly high or low in my blood test?
• Could any of my current medications be affecting my white blood cell count?
• What are the potential causes for my white blood cell count being outside the normal range?
• Are there any lifestyle changes you would recommend to support my immune system?
• Do I need any further tests to investigate my white blood cell count?