The typical changes in the differential blood count during stress and acute illnesses are called stress leukograms . It is triggered by high cortisol levels and is therefore also typical of Cushing's syndrome , but not specific. A stress leukogram is characterized by an increase in neutrophil granulocytes in the blood ( neutrophilia ), a decrease in lymphocytes ( lymphopenia ) and eosinophils ( eosinopenia ), and often an increase in monocytes ( monocytosis ).
Neutrophilia is triggered by an increased release of mature granulocytes from the bone marrow , possibly also by the migration of granulocytes from the periphery into the bloodstream and by a reduced migration from the bloodstream to the periphery. Lymphopenia is caused by a redistribution of the lymphocytes in the circulating blood, possibly also by a lysis of the lymphocytes. Eosinopenia is caused by steroid-dependent storage of eosinophils in the bone marrow and other tissues. In monocytosis, too, a redistribution of monocytes from the periphery into the circulating blood is assumed to be the cause.