Range of White Blood Count in Children

Updated February 28, 2017

The white blood cell count is a test ordered by a doctor to determine if a child is suffering from an infection, disease or allergic reaction. When the body is fighting one of these conditions, the white blood cell count will be higher than normal. If a patient is susceptible to infection or disease, his white blood count may be lower than normal.


White blood cells are the cells that attack and remove bacteria and viruses from the body. A low white blood cell count could indicate if your child is at risk of infection and a high white blood cell count can show if an infection, virus or disease may already be present.

White Blood Cell Types

Several major white blood cell types make up the overall white blood cell count. These cells include neutrophils, lymphocytes, monocytes, basophils and eosinophils. The numbers of each of these cell types in the white blood count helps a doctor determine how healthy your child's immune system is. Too many or too few of any of these types of blood cells can affect your child's immune system.

Healthy Range

A healthy range for children is between 4,500 to 10,000 white blood cells per microliter, but an exact range depends on the child's age and sex. Normal values vary with age. White blood cell counts are highest in children under one year old and continue to decrease into adulthood. Individual ranges exist for the five main types of cells that make up the overall white blood cell count.

Unhealthy Range

Any number that falls above or below the healthy range is considered unhealthy. In addition to the overall white blood cell count range, your doctor may pay particular attention to the ranges of the particular cells within the white blood count. The lymphocytes in the white blood cell count for children will be important to your doctor. A lymphocyte level above 40 per cent or below 15 per cent may indicate a health risk for your child.

Abnormal Results

An abnormally low white blood cell count means that a patient is experiencing leukopenia, which may be due to bone marrow failure, radiation or an infection or disease that is affecting the spleen or liver. An abnormally high white blood cell count means that a patient is experiencing leukocytosis. Leukocytosis can occur due to anaemia, infectious disease, leukaemia, allergies or extreme physical or emotional distress.

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About the Author

Fitzalan Gorman has more than 10 years of academic and commercial experience in research and writing. She has written speeches and text for CEOs, company presidents and leaders of major nonprofit organizations. Gorman has published for professional cycling teams and various health and fitness websites. She has a Master of Arts from Virginia Tech in political science and is a NASM certified personal trainer.