Why does high white blood cells show in test?

Leukocytosis, or an elevated white blood cell count, can be indicative of several underlying conditions, ranging from infections to inflammatory disorders. White blood cells, also known as leukocytes, play a crucial role in the body's immune system by defending against infections and foreign particles. When there is an increased demand on the immune system, such as during an infection or inflammation, the bone marrow produces and releases more white blood cells into the bloodstream. This elevated white blood cell count is detected in blood tests, commonly referred to as high white blood cells.

Here are some common causes of high white blood cells:

1. Infections:

- Bacterial infections: Bacterial infections, such as pneumonia, urinary tract infections, or sepsis, often lead to an increase in white blood cell production to combat the invading bacteria.

- Viral infections: While some viral infections can cause a drop in white blood cell count, others, such as influenza or infectious mononucleosis, can result in elevated white blood cell levels.

2. Inflammation:

- Chronic inflammatory diseases: Conditions like rheumatoid arthritis, inflammatory bowel disease, or Crohn's disease cause persistent inflammation, which can lead to high white blood cell counts over a prolonged period.

- Acute inflammation: Severe tissue injury, burns, or pancreatitis can trigger a rapid increase in white blood cells as the body tries to heal and repair the damaged tissue.

3. Blood disorders:

- Leukemia: Leukemia is a type of cancer that affects the blood and bone marrow, resulting in an abnormal production of white blood cells. Leukemia often presents with significantly high white blood cell counts.

- Other blood disorders: Certain conditions such as polycythemia vera or sickle cell anemia can also lead to elevated white blood cell levels.

4. Stress and certain medications:

- Emotional or physical stress: Intense emotional stress or physical exertion can temporarily elevate white blood cell counts.

- Medications: Some drugs, such as corticosteroids, can suppress the production of white blood cells, while others, such as lithium or chemotherapy, may cause an increase in white blood cells as a side effect.

It is important to note that a high white blood cell count alone does not provide a conclusive diagnosis. Further tests and evaluations by a healthcare professional are necessary to determine the underlying cause and appropriate treatment for elevated white blood cell levels.