Abscess at the root of the tongue is a typical symptom of acute lingual tonsillitis, in which the lymphoid tissue at the root of the patient’s tongue is granularly elevated, congested, swollen, and connected to the lower end of the tonsils, and in severe cases there are local ulcers and purulent secretions adhering to the root of the tongue. The diagnosis of tongue root abscess is mainly based on checking the number of lymphocytes, a group of morphologically similar and functionally different non-homogeneous cells, which are specific immunoreactive cells and play a central role in the immune response. It varies less in number in general disease and often increases or decreases in relative proportion due to a decrease or increase in other cells in the blood. The qualitative changes in lymphocytes are more valuable than the quantitative increases or decreases, and if the subpopulations of lymphocytes are not measured, the determination of clinical significance is somewhat limited. Procedure: (1) Retain urine for 12 h from 8 p.m. to 8 a.m. the next day, and accurately measure urine volume and specific gravity. (2) Accurately aspirate 10 ml of well-mixed urine in a graduated centrifuge tube, centrifuge at 1500 r/min for 10 min to precipitate, discard 9 ml of supernatant, and mix the remaining 1 ml thoroughly. (3) Aspirate 1 small drop of the mixed urine sediment into a hemocytometer plate, count the number of cells in 10 large squares and the number of tubulars in 20 large squares, and calculate the number of cells and tubulars in 12h nocturnal urine. Increased: seen in viral infections, tuberculosis, pertussis, infectious mononucleosis, infectious lymphocytosis, lymphocytic leukemia, lymphosarcoma. Decreased: seen in cellular immunodeficiency diseases, acute phase of certain infectious diseases, radiation sickness, application of adrenocorticosteroids, anti-lymphocyte globulin therapy, lymphocytopenia, immunodeficiency diseases, gammaglobulin deficiency, etc.