The symptoms of high lymphocyte percentage may be caused by the following reasons: a. Infectious diseases, viral infections such as measles and chicken pox are the most common causes of high lymphocyte percentage; b. Tumor diseases, if you have lymphoma or other tumor diseases, high lymphocyte percentage may occur during the recovery period or after organ transplantation; c. Hematological diseases. If the patient suffers from blood diseases such as aplastic anemia, high lymphocyte percentage is one of the symptoms of the disease. It should be noted that if the symptoms of high lymphocyte percentage are not continuously increased, but only occasionally increased, it may be a normal functioning of the body, and there is no need to worry too much.