The absolute lymphocyte value in normal human body ranges from (1.1-3.2)×10^9/L. If a patient has a low absolute lymphocyte value, you can first consider whether it is due to a decrease in immunity, such as long-term radiation therapy, which may lead to a low absolute lymphocyte value in the body, and it can be gradually improved by changing the treatment under the guidance of a doctor. In addition, patients should also consider bacterial or viral infections or diseases related to immune system disorders, which may also cause low absolute lymphocyte values, such as anemia, rheumatoid arthritis, systemic lupus erythematosus, AIDS, etc. Patients need to be further examined to clarify the type of disease and to treat the original disease: 1. Anemia: Due to the decrease in the capacity of human peripheral blood erythrocytes, they cannot adequately supply oxygen to tissues and organs. At the same time, the immunity of the body is low and the lymphocytes are attacked, resulting in low absolute value of lymphocytes. Treatment should be directed at the cause of anemia, such as iron deficiency anemia with iron supplementation and megaloblastic anemia with folic acid or vitamin B12. 2. Anti-infective drugs such as penicillin or erythromycin, and non-steroidal anti-inflammatory drugs such as ibuprofen and aspirin can be selected for treatment under the guidance of a doctor, and glucocorticoids should be used promptly if the patient shows cardiac involvement; 3. dysfunction and kidney damage. Glucocorticoids such as methylprednisolone and prednisone are the main drugs for the treatment of SLE, and can be combined with immunosuppressive drugs for treatment. 4. AIDS: As HIV attacks the immune system of the body, lymphocytes are reduced, resulting in low absolute lymphocyte values and vulnerability to bacterial and viral infections, with symptoms such as fever, fatigue, abdominal pain and diarrhea. The disease is a lifelong disease and cannot be cured yet, but patients can slow down the disease process with active medication, which commonly includes lamivudine, tenofovir, zidovudine, abacavir, etc., and can be treated symptomatically according to the symptoms. In addition, it should also be considered that the disease is caused by other diseases receiving drug treatment, such as long-term application of adrenal glucocorticosteroids such as prednisone and other drugs, the absolute value of lymphocytes may appear low, need to adjust the use of drugs under the guidance of doctors, and thus alleviate the symptoms. There are many reasons for low absolute lymphocyte values. Patients need to improve various examinations according to clinical symptoms under the guidance of doctors and actively cooperate with treatment after clear diagnosis to avoid further aggravation of the disease.