The reason why you don’t want to eat can be due to digestive system diseases, respiratory system diseases, endocrine system diseases and so on. 1. Digestive system diseases: when the patient suffers from acute gastroenteritis, chronic pancreatitis and other diseases, it is easy to nausea, abdominal distension, vomiting, loss of appetite and other symptoms, resulting in a difficult not want to eat. 2. Respiratory system diseases: if the patient suffers from lung cancer, pneumonia, tuberculosis and other diseases, it may lead to fatigue, low-grade fever and other symptoms, resulting in the phenomenon of not wanting to eat. 3. Endocrine system diseases: If the patient suffers from hypothyroidism, hypoadrenocorticism and other diseases, the patient will show fatigue, loss of appetite and so on. It is recommended that patients who do not want to eat, go to the hospital in time to identify the cause of the disease and receive treatment.