High lymphocytes and low neutrophils are usually caused by two major types of diseases, commonly such as hematologic diseases, which can include acute lymphoblastic leukemia, acute myeloid leukemia, acute infectious lymphocytosis, and mononucleosis. Infectious diseases can also have high lymphocytes, while low neutrophils are usually caused by viral infections, such as respiratory viral infections, gastrointestinal viral infections, genitourinary viral infections, and viral infections of the skin system, such as herpes zoster, can have high lymphocytes. In the case of low neutrophils, such as peripheral inflammatory response syndrome and sepsis, there can also be diseases with high lymphocytes and low neutrophils. In addition, some rare diseases such as tumors, connective tissue diseases, and tuberculosis can also have such symptoms.