What is the normal blood count in a human?

Normal red blood cell counts range from 4.2 to 5.4 million cells in women and 4.7 to 6.1 million cells per microliter in men, according to the National Library of Medicine. Healthy persons should have 4,500 to 10,000 white blood cells per microliter of blood.

Causes for high red blood cell counts include dehydration, kidney disease and smoking; low numbers may be linked to autoimmune disease, blood loss, chronic kidney disease, poor diet or nutrition and other conditions.

High numbers of white blood cells indicate leukocytosis, which may be rooted to infectious or inflammatory disease, leukemia, severe emotional or physical stress or tissue damage.