Physiological leukocytosis is seen in

Physiological leukocytosis (i.e.,increase in the number of circulating leucocytes in the absence of infection or tissue injury) has no clinical significance. It is seen in the following conditions: 1. Normal infants: The count may be as high as 18-20,000/mm3 but it returns to normal level within 1-2 years. 2. Food intake and digestion ("digestive leukocytosis"):There is a mild increase which returns to normal within an hour or so. 3. Physical exercise. 4. Mental stress. 5. Pregnancy: The count may be quite high, especially during the first pregnancy. 6. Paurition: The high TLC is possibly due to tissue injury, pain, physical stress and hemorrhage. 7. Extremes of temperatures: Exposure to sun or to very low temperature can increase the WBC count.