Emotional Stress
Leukocytosis is often noted to occur more frequently in people with affective disorders and some other mental conditions. When you experience an intensity of your emotional responses, such as fear or anxiety, the immune system of your body will operate to fight against negative thoughts and other harmful things. This increases the production of white blood cells. When you are suffering from emotional stress or other mental conditions for an extended period, it would affect normal white blood cell production, thus causing leukocytosis. [9]
