Lack of appetite refers to loss of appetite. There are many reasons for this symptom, and the common causes include emotional factors, taking certain medications, and organic lesions. 1. Emotional factors: emotional factors such as high mental tension and emotional upset may cause loss of appetite. After the emotions are relieved, the symptoms of loss of appetite will often disappear. Short-term loss of appetite is often due to emotional factors, patients are advised to reasonably regulate their own emotions and avoid overwork. 2. Taking drugs: taking non-steroidal anti-inflammatory drugs (such as aspirin, ibuprofen, etc.), antibiotics (such as azithromycin, cefdinir, etc.), antiepileptic drugs (such as carbamazepine, phenytoin sodium, etc.) may lead to loss of appetite. 3.Organic lesions: (1) Digestive system diseases: acute and chronic gastritis, gastric cancer, inflammatory bowel disease, acute and chronic hepatitis, cirrhosis and other common digestive system diseases can lead to symptoms of loss of appetite. (2) Endocrine diseases: hypothyroidism, hypoadrenocorticism, hypopituitarism, etc. Due to metabolic abnormalities, patients with these diseases will experience symptoms of loss of appetite to varying degrees. There are many reasons for loss of appetite, if the patient has a long-term loss of appetite, it is recommended to go to the hospital for examination, to clarify the cause of the disease, and follow the doctor’s instructions for treatment.