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 »

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 »

Diseases that cause high white blood cell counts include bacterial infections, anemia, inflammatory diseases and leukemia. The body also produces more white blood cells as a reaction to stress, burns, cigarette smoking a... 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 high white blood cell count may indicate anemia, infection, allergic reaction or leukemia, states MedlinePlus. Other causes include extensive tissue damage, cigarette smoking and severe mental or physical stress. Takin... More » Health Medical Ranges & Levels

A low white blood cell count can be related to a number of causes, including viral infections, cancer and diminished immune system function, according to MayoClinic. Detailed blood screening is the first step necessary t... More »

A congenital or autoimmune disorder, cancer, a viral infection, an overwhelmingly strong infection, or certain drugs may cause a low white blood cell count, Mayo Clinic advises. Damage to bone marrow, which produces whit... More »