Monocyte count refers to the number of monocytes detected. Monocytes are an important component of human blood cells and are the largest type of cells in the blood, which are involved in the body’s defense function, clearing away injured and senile cells in the body and participating in the immune response. Therefore, monocytes can be increased if there is an infection or a blood disorder in the body, or if there is an upper respiratory tract infection, typhoid fever, tuberculosis, malaria or other diseases. Mononucleosis, lymphoma, and Hodgkin’s disease can all cause an increase in monocyte count, but in infants and young children, physiological monocyte count increases are more likely to occur and should be differentiated.