Blood that flows through the body is whole blood. It is composed of white blood cells, red blood cells and platelets. The white blood cells are the army; they detect and fight infection. In children as in all people, the white blood cell count reveals whether an individual is fighting infection.
Newborns have the highest white blood cell count. Typical newborns have a count ranging from 9,000 to 30,000 leukocytes. Leukocyte is another name for a white blood cell.
After the first couple of weeks of life, white blood cell count is not age specific. A healthy child and a healthy full-grown adult will have counts that mirror one another. The normal leukocyte count is 4,000 to 10,800 in a healthy human.
A low white blood cell count is below 3,500. Reasons for the decrease can include an infection that is using up the white blood cells faster than they can regenerate; cancer; congenital and autoimmune disorders; and medications. A child with a low white blood cell count may not exhibit any of the symptoms of fighting off an illness; the only cue may be a fever of 38.1 degrees C or above. If you have any reason to believe your child's count has fallen, such as a history of this issue, and your child has a fever, call your paediatrician immediately.
Typically, if a child's white blood cell count is high, the body is producing an army to fight an infection. Elevated levels can be due to a bone marrow disease or an immune system disorder, or it can be a reaction to medication. Typical childhood diseases associated with a high white blood cell count include whooping cough and measles. If your child has a high white blood cell count, her paediatrician will order tests to pinpoint the cause.
Why Get Tested
Typically, a blood cell count is done each year at your child's physical just to ensure that your child is indeed healthy and nothing unseen is lurking. Outside of the normal physical, a white blood cell count can be ordered to test for an infection, reveal a disease or monitor the progress of a treatment for a disease or infection. If the white blood cell count is within the normal range, the treatment is a success.