There are many reasons for the lack of appetite, such as: mental factors, digestive system diseases, medication and so on. It is recommended to go to the hospital to find out the cause of the lack of appetite. 1. Mental factors: excessive stress, overstress, fatigue, anxiety, depression and other mental factors can lead to a lack of appetite. At this time, we should maintain a comfortable mood, relax, pay attention to relieve stress, and maintain a regular diet and work and rest. 2. Digestive system diseases: mainly caused by gastritis, peptic ulcer, intestinal obstruction, tumor, acute and chronic hepatitis, acute and chronic pancreatitis and other diseases. To consult a doctor in time, for the cause of the disease, symptomatic supportive treatment. You can use some drugs to promote gastrointestinal motility to improve appetite. 3. Drug factors: many drugs can cause loss of appetite, such as chemotherapy drugs, non-steroidal anti-inflammatory drugs, etc., it is recommended to follow the doctor’s instructions for medication.