LEUKOCYTOSIS

abnormally high number of white blood cells (leukocytes) in the blood circulation, defined, for statistical purposes, as more than 10,000 leukocytes per cubic millimetre of blood. Leukocytosis commonly occurs after strenuous exercise, convulsions (e.g., epilepsy), strong emotional reactions, ether anesthesia, the administration of epinephrine, pregnancy and labour, and oxygen lack (as in the early phases of adaptation to high altitude). Leukocytosis is also observed in many disease states, including infections, parasitic infestations, intoxications (metabolic or chemical), chronic diseases (e.g., leukemia), and allergic reactions.