Low lymphocytes refer to a decreased number of lymphocytes, which are a type of white blood cell involved in the immune response. Lymphocytes play a crucial role in fighting off infections and diseases. A low lymphocyte count, also known as lymphocytopenia, can be caused by various factors, including viral infections, certain medications (such as chemotherapy drugs), immunodeficiency disorders, autoimmune diseases, bone marrow disorders, and some types of cancers. It is important to consult with a healthcare professional for a proper evaluation, diagnosis, and management of low lymphocyte counts, as the underlying cause needs to be determined and treated accordingly.