There are several possible causes for a high white blood cell count. This count is high when there are more disease-fighting cells in your body. The technical term for this condition is leukocytosis.
Different medical practices may have different limits by which they define high white blood cell count. A count of 10,500 leukocytes in one microliter of blood is widely accepted as a high count. The threshold may vary between sex and age.
White blood cells are categorized by five subtypes, and each type has a different activity in fighting disease. When you get the results of your white blood cell count, they will usually specify what the levels are of all the different types. Usually, a high count is only caused by an increase in one type of white blood cells.
A high white blood cell count is indicative of an immune system problem that increases their production; a disease in your bone marrow that causes high blood cell production; a reaction to some drug that is used to enhance cell production; or the increase expected when your body is fighting off an infection.
There are some more specific reasons why your white blood cell count may be high:
Acute lymphocytic leukemia (ALL) is a cancer that lives in the bone marrow and blood. This disease is a rapidly progressive one. Children are more affected by this than any other type of cancer, although adults can develop the disease as well.
Drugs like epinephrine and corticosteroids can affect your white cell count.
Measles is an infection that affects mainly the respiratory tract. It is very contagious. The signs include skin rash, fever, sore throat, inflamed eyes, runny nose and cough. The measles vaccine is an excellent way to protect children against this disease, but outside of the civilized countries, many children are not vaccinated. This disease will spread rapidly among people who have not had the vaccination.
Rheumatoid arthritis is a serious type of arthritis from which you will experience joint damage and pain. It attacks your joints' lining and this causes swelling. In turn, that leads to throbbing, aching pain and possibly eventual deformity. Rheumatoid arthritis, also called RA, can make even the easiest of normal activities hard to accomplish.
Some of the other causes of high white blood cell count include:
Stress, be it emotional or physical
Tissue damage, like one receives with burns
Acute or chronic myelogenous leukemia
Chronic or acute lymphocytic leukemia
Severe allergic reactions
Other viral infections
Other bacterial infections