Immunity can be boosted in three ways: strengthening exercise and nutrition to enhance physical fitness; using immunity-boosting drugs such as splenic polypeptide and thymofaxine as prescribed by the doctor; and treating the primary disease that causes immunity to be low. Causes of low immunity include physiological factors such as staying up late, fatigue and malnutrition, and diseases such as lymphoma, multiple myeloma, rheumatoid arthritis, systemic lupus erythematosus and malignant tumors. For low immunity caused by physiological factors, immunity can be gradually restored after adequate rest, strengthening exercise and increasing nutrition. For low immunity caused by diseases, the use of splenic polypeptide, thymofaxine and other drugs to regulate immunity can be prescribed by the doctor, so as to enhance the body’s immunity. However, it is more crucial to treat the specific cause of the disease, only after the primary disease can be treated can the immunity be fundamentally improved. It is recommended that patients with low immunity consult a doctor in a timely manner, improve the relevant examinations to clarify the specific causes of the disease, and then by the physician according to the patient’s specific condition to develop a treatment plan, and the patient should pay attention to personal hygiene, dietary hygiene, and avoid entering and exiting densely populated places in order to prevent infections. The use of drugs must follow the doctor’s instructions, not blindly use their own drugs, so as not to cause adverse consequences.