About white blood cells
White blood cells, medically referred to as leukocytes, are an essential component of the immune system that helps the body fight against infections.1 White blood cells are found in the blood, which allows them to circulate throughout the body and easily reach areas of infection.2 White blood cells can be further divided into subcategories: neutrophils, monocytes, eosinophils, lymphocytes, and basophils.1 Each subcategory has its own specialised role that contributes to the overall function of white blood cells.
Make up of blood (blood cell types, proportions etc)
Blood is made of a diverse range of components that allow it to carry out its functions of nutrient delivery, transportation of cellular waste, and aiding in infection control. Blood is composed of four main components: red blood cells (erythrocytes), white blood cells (leukocytes), plasma, and platelets (thrombocytes).3
Plasma is the liquid component of blood; plasma is made of sugars, proteins, fats, and salts. Plasma functions as the main medium through which blood cells, nutrients, and waste products transport through to circular the body.3,4 According to the American Red Cross, 55% of the blood is composed of plasma.4
Red blood cells, also known as erythrocytes are the most common blood cell, they account for up to 45% of the blood’s volume.3 Red blood cells have special structural features such as a flexible, biconcave shape that allows them to fit within the smallest of blood vessels. Red blood cells contain haemoglobin, a protein that allows them to carry and deliver oxygen and carry and remove carbon dioxide in the body.3 Haematocrit is the percentage of blood volume that is made up by red blood cells. It is used as a diagnostic measure of red blood cells to identify certain conditions.3
Platelets are small cell fragments that are involved in the process of blood clotting. Platelets accumulate in an injured area and adhere to the lining to form a base for blood clotting to then begin. The newly formed base functions as a protective layer for the wounds and prevents blood from spilling out from the injured area. Platelet levels are also used as a diagnostic reference, as elevated platelet levels are associated with strokes and heart attacks.3
White blood cells are the infection-fighting components of the blood. White blood cells have a smaller population than red blood cells, they only account for 1% of the blood total volume.3 There are various subcategories of white blood cells that have different roles in the infection fighting response. Elevated white blood cell count is used as an indicator of inflammation or infection in the body, as white blood cell levels increase in response to these pathological conditions.1,4
Role of white blood cells
The various types of white blood cells have important immune functions within the body. The role of white blood cells ultimately depends on the type:
- Neutrophils: These white blood cells help protect the body from infections by killing infection causing agents such as bacteria, viruses, fungi, and other types of debris.1,2 Majority of white blood cells are neutrophils, neutrophils scavenge for infection causing agents and then destroy them to rid the body of infection2
- Basophils: Basophils make up less than 1% of all white blood cells, they are responsible for producing an allergic reaction following exposure to an allergen.1,2 Allergic reactions are essentially a defence mechanism against the offending allergen. Basophils produce symptoms such as coughing, sneezing, and inflammation1
- Eosinophils: Eosinophils respond to infections caused by parasites and cancerous cells.1 They also assist basophils in producing an immune response to rid the body of any offending substances.1
- Lymphocytes: Lymphocytes are a type of white blood cells that can be divided into further categories: T lymphocytes, B lymphocytes, and Natural killer cells.1 T lymphocytes recognise and destroy infection causing agents. B lymphocytes produce antibodies that aid the immune response in producing a response to infectious agents.2 Natural killer cells specifically recognise and attack viral and cancer cells.2
- Monocytes: Monocytes are white blood cells that fight off chronic infections while also clearing out damaged/injured cells.1
High white blood cell count
Causes and risk factors
High white blood cell count, also known as leukocytosis is a condition in which white blood cells are abnormally high.5 High white blood cell count can be caused by the following:
- Chronic infections: Chronic infections causes the white blood cell count to rise in response to the infection5
- Persistent physical and/or emotional stress: Physical and emotional stress can cause rises to white blood cell count.6
- Certain forms of leukaemia: Leukaemia is a cancer form that affects the white blood cells. Certain leukaemia forms causes a rise in white blood cells.5,6 Acute myelogenous leukaemia is a form that is associated with a significant increase in white blood cell count.
- Immune conditions: Immune conditions such as lupus and rheumatoid arthritis can cause a rise of white blood cells due to imbalances within the immune system causing a rise in certain cells and a fall in others.5
- Spleen removal: The spleen is an organ that functions to make white blood cells and filter the blood. Removal of the spleen can cause a rise of the white blood cells count.5
There are also risk factors that are associated with high white blood cell count, these include:
- Exposure to allergens: People with allergies are at risk of having a high white blood cell count as exposure to allergens can cause an allergic response in these individuals6
- Smoking: Smoking has many adverse effects throughout the body while also making individuals susceptible to infections and having higher inflammation than non-smokers.6 As a result, smoking also increases one’s risk of having a high white blood cell
- Excessive physical or emotional stress: All forms of stress can increase one’s risk of high white blood cell count. Stress takes a toll on the body making it more susceptible to infection which may leader to higher levels of white blood cells.6
- Poor dental hygiene: Inflammation of the gum and associated areas caused by poor dental hygiene can lead to rise in white blood cell count.6
Symptoms of high white blood cell count are associated with the condition that causes it. However, symptoms can overlap due to the common symptom of a rise in white blood cell count. Symptoms include:
- Easily bruising5,6
- Breathing difficulties6
- Unexplained weight loss5
As symptoms worsen, individuals may experience stroke, vision problems, and internal bleeding (5).
High white blood count and abdominal pain
Peritonitis is a condition in which the peritoneum, the tissue lining of the abdomen is inflamed. It is a serious and potentially deadly disease.7 Peritonitis is typically caused by bacterial infection. It can also be caused by hole in the other digestive organs such as the stomach and infection following surgery.7 One of the methods to diagnose peritonitis involves examining of the fluid within the peritoneum is examined for high levels of white blood cells.8 The high white blood cell levels can indicate the presence of inflammation or infection within the peritoneal area.8
Gastroenteritis, commonly known as the stomach flu, is a condition in which the intestines (small and large intestine) are inflamed.9 Gastroenteritis can be caused by viruses, bacteria, and parasites. Viruses are the most common cause of the condition.9 Gastroenteritis can cause symptoms such as nausea, vomiting, and aches and pains.9 Gastroenteritis also results in a rise of white blood cells, especially neutrophils (the white blood cells that fight against bacteria and viruses) as the immune system tries to fight and destroy the offending infectious agents.9
Infections of any part of the abdominal area (stomach, small intestine, large intestine, liver etc,) can lead to a rise in white blood cell count. As white blood cells are an integral part of the immune system’s defence against infection and inflammation, their count rises in inflammatory conditions and during infection. The specific type of white blood cells that rise ultimately depends on what type of infection one is suffering from. Viral, bacterial and parasitic infections result in a rise of neutrophils.2 T lymphocytes and B lymphocytes rise as the immune system attempts to clear the infection from the body.1,2
Digestive issues can also result in high white blood white count, however, it varies depending on the cause of the digestive issues. An example of this is Crohn’s Disease; Crohn’s is a chronic digestive condition that is characterised by inflammation of the digestive tract can lead to severe abdominal pain and poor nutrient absorption.10 Due to the inflammatory nature of the disease, individuals with Crohn’s have elevated white blood cell count.
A high white blood cell count during pregnancy is usually not a cause of concern. Pregnancy is associated with elevated white blood cell count due to the stress that being pregnant places on the body.11 As a result, pregnant women’s white blood cell count is continuously monitored throughout their gestation period. On average, a pregnant woman’s total blood volume will increase up to 50%, thus as a result, one can expect their white blood count to also experience an increase.11
Leukaemia is cancer that affects the white blood cell count. Acute myeloid leukaemia and acute lymphoblastic leukaemia are associated with a rise in white blood cells. This is due to the pathology of the two. In patients with acute myeloid leukaemia, their white blood cells grow and divide rapidly within a short period of time, resulting in an abnormally high number of them present in the blood.12 White blood cells can also become too great for the blood to carry and spread to other organs, resulting in further complications. In acute lymphoblastic leukaemia, the lymphocytes (one of the types of white blood cells) grow and divide rapidly, causing them to quickly enter the blood.13 They then can spread to other organs, causing further complications. Not all forms of leukaemia are associated with a high white blood cell count as the white blood cells may sequester in the bone marrow and other areas of the body.12,13
To screen for high white blood cell count, medical professionals may perform blood tests to detect the levels of white blood cells within the blood. Blood samples are the most common form of screening for white blood cells as it allows them to get an accurate measurement of their number within the blood.2 However, medical professionals may test other body fluids for the presence of white blood cells such as the bone marrow if they suspect an individual is suffering from a certain condition.2 White blood cell are often screened to test for allergies and infection, to try to diagnose leukaemia, and record the progression of certain immune conditions.2
Treatment for high white blood cell count ultimately depends on the cause of the elevated white blood cells.2 As an increase in white blood cells are often caused by infection and allergies, the rise in white blood cell count usually subsides with treatment. However, in more serious conditions such as gastroenteritis and peritonitis treatment requires treating the inflammation. In leukaemia patients with high white blood cell count, patients require chemotherapy, certain medications, and stem cell therapy to treat the condition.13
White blood cells are a type of blood cell that are involved in helping the body fight off infections and inflammation caused by infections, allergens, and disease.1 There are various subtypes of white blood cells that deal with certain infections and pathological conditions. A high white blood cell count is often a sign of the presence of infection or inflammation within the body as white blood cells population rises to help the immune system fight and clear out harmful substances.2,3 Conditions such as peritonitis, gastroenteritis, infections of the digestive system, pregnancy and leukaemia result in high white blood cell count.7,13 As a result, the treatment option for high white blood cell count ultimately depends on the condition is causing a rise in white blood cells.
- Cleveland Clinic. Function of White Blood Cells [internet]. 2021 July 23 [cited 2022 August 17]. Available from: https://my.clevelandclinic.org/health/body/21871-white-blood-cells
- Nall R, Weatherspoon D. What to know about white blood cells [internet]. 2020 January 9 [cited 2022 August 17]. Available from: https://www.medicalnewstoday.com/articles/327446#test
- American Society of Hematology. Blood Basics [internet]. 2022 [cited 2022 August 17]. Available from: https://www.hematology.org/education/patients/blood-basics
- American Red Cross. The Importance of Plasma in Blood [internet]. 2022 [cited 2022 August 17]. Available from: https://www.redcrossblood.org/donate-blood/dlp/plasma-information.html#:~:text=Plasma%20is%20the%20liquid%20portion,Plasma%20is%20about%2092%25%20water.
- Link R, Balingit A. What is Leukocytosis [internet]. 2021 August 3 [cited 2022 August 17]. Available from: https://www.healthline.com/health/leukocytosis
- Cleveland Clinic. High White Blood Cell Count [internet]. 2022 January 19 [cited 2022 August 17]. Available from: https://my.clevelandclinic.org/health/diagnostics/17704-high-white-blood-cell-count
- John Hopkins Medicine. Peritonitis [internet]. 2022 [cited 2022 August 17]. Available from: https://www.hopkinsmedicine.org/health/conditions-and-diseases/peritonitis
- Cassata C, Sinha S. What is Peritonitis? Symptoms, Causes, Diagnosis, Treatment and Prevention [internet]. 2020 November 23 [cited 2022 August 17]. Available from: https://www.everydayhealth.com/peritonitis/guide/
- Cleveland Clinic. Stomach Flu (Gastroenteritis) [internet]. 2020 April 26 [cited 2022 August 17]. Available from: https://my.clevelandclinic.org/health/diseases/12418-gastroenteritis
- Mayo Clinic. Crohn’s disease [internet]. 2022 August 6 [cited 2022 August 17]. Available from: https://www.mayoclinic.org/diseases-conditions/crohns-disease/symptoms-causes/syc-20353304#:~:text=Crohn's%20disease%20is%20a%20type,fatigue%2C%20weight%20loss%20and%20malnutrition.
- Brennan D, Sruthi M, Allarakha S. What Does High White Blood Cell Count Mean When Pregnant? [internet]. 2022 March 3 [cited 2022 August 17]. Available from: https://www.medicinenet.com/high_white_blood_cell_count_in_pregnancy/article.htm
- American Cancer Society. What is Acute Myeloid Leukemia? [internet]. 2022 [cited 2022 August 18]. Available from: https://www.cancer.org/cancer/chronic-myeloid-leukemia/about/what-is-cml.html
- American Cancer Society. What is Acute Lymphocytic Leukemia? [internet]. 2022 [cited 2022 August 18]. Available from: https://www.cancer.org/cancer/acute-lymphocytic-leukemia/about/what-is-all.html