The proportion of neutrophils is the highest, accounting for 50-70% of total leukocytes; the ratio of lymphocytes accounts for 20-40%; the ratio of eosinophils accounts for 4-8%; the ratio of monocytes accounts for 3-8%; and the ratio of eosinophils accounts for 0-1%. Leukocytes are an important component of the body’s immune system, and different types of leukocytes are involved in the body’s defense in different ways.
Neutrophils play an important role in bacterial infectious diseases. Acute infections caused by various germs such as pneumonia and appendicitis, serious tissue injuries such as major surgery and myocardial infarction that cause neutrophil elevation, and various etiologies such as leukemia and malignancy can lead to abnormal leukocytosis. Lymphocytes play a major role in various viral infectious diseases such as chickenpox and hepatitis, and in certain infectious diseases. In addition, eosinophils and basophils play an immune role in certain allergic diseases such as bronchial asthma, urticaria, and parasitic infections. On the other hand, leukopenia occurs when hematopoietic disorders, long-term hormone use, or post-radiation or chemotherapy suppress hematopoiesis.
In summary, when the body’s environment is stable, the number of leukocytes is maintained at a normal range to play an immune surveillance role, and when various abnormalities occur in the body, such as infections, the number of leukocytes will change accordingly to play a defensive function.