A high percentage of lymphocytes is not AIDS. Because AIDS is also known as a human acquired immune virus infection, the number of human helper T lymphocytes decreases after HIV infection, which means that the percentage of lymphocytes in the body decreases after HIV infection, not increases. Therefore, an increased lymphocyte percentage is not AIDS. There are many reasons for an increased lymphocyte percentage. Commonly, an increased lymphocyte percentage can occur with general viral infections such as influenza virus and rubella virus infections. In addition, high lymphocyte percentage can also occur when suffering from myeloproliferative disorders. If the lymphocyte percentage is abnormally high, the most common causes are acute lymphocytic leukemia and chronic lymphocytic leukemia, which end up with a significantly high lymphocyte percentage due to the proliferation of leukemia cells in the bone marrow.