An elevated white blood cell count occurs when the white blood cells, also referred to as leukocytes, increase in response to infection or illness, according to MedlinePlus. Specific causes of high white blood cell count... More »

Causes of an elevated white cell count, or leukocytosis, include diseases of the bone marrow or the immune system, reactions to drugs and leukemia, says Mayo Clinic.The patient may also be fighting off a viral or bacteri... More »

A urinary tract infection is a common cause of white blood cells appearing in the urine, according to MedicineNet. While white blood cells from the opening of the urethra (in both men and women) or the vagina (in women) ... More »

When infections or acute stress cause the production of white blood cells to increase, an increase in the percentage of immature cells also occurs, and this change is what is referred to as a "shift to the left," accordi... More »

The Western Journal of Medicine recommends that patients who have a white blood cell count below 500 per microliter and signs of infection seek immediate hospitalization and antibiotic therapy. White blood cell counts be... More »

A high white blood cell count typically indicates a bacterial or viral infection; a disorder of the immune system; a reaction to medication; leukemia; allergic reaction; stress; or smoking, as stated by Mayo Clinic. Tube... More »

A normal white blood cell count ranges from 4,500 to 10,000 white blood cells per microliter of blood, according to MedlinePlus. Since the normal range may be somewhat different depending on the laboratory, measurements ... More » Health Medical Ranges & Levels