The normal range for lymphocytes in adults is 1000 to 4800 lymphocytes per microliter of blood, according to the National Heart, Lung, and Blood Institute. The normal range of lymphocytes in children is typically between 3000 and 9500 lymphocytes per microliter of blood.
Lymphocytes are a type of white blood cell that makes up approximately 20 to 40 percent of all of the white blood cells in the human body, states the National Heart, Lung, and Blood Institute. The cells are created by the bone marrow and help to protect the body from foreign pathogens and infections. People with low lymphocyte counts may be at risk of developing frequent infections.