The cause of night sweats (abnormal sweating after going to sleep and stopping after waking up) and low-grade fever can generally be considered to be yin deficiency, but specific cases need to go to the hospital, identify the cause of the disease, and be treated under the guidance of a medical professional who can identify the cause of the disease. Yin deficiency is mainly caused by the depletion of yin fluid after a prolonged illness or fever. When yin fluid is depleted, the body loses moistening and nourishment, and yang-heat qi is relatively strong, making it easy to generate internal heat, which can be manifested as night sweats, low-grade fever and other symptoms. Clinical treatment of yin deficiency usually focuses on nourishing yin and clearing heat (nourishing yin essence and removing heat), and can be treated with medications such as Dahuiyin Pills under the guidance of a physician. Attention to the drug allergy is prohibited, allergic people should be cautious, diabetic patients are prohibited from taking, pregnant women should be cautious, cold patients should not take, cold patients are not applicable. It is recommended that patients in need of timely medical treatment, do not blindly use their own medication, so as not to delay the condition.