There are many diseases that cause lack of appetite and desire to eat and vomit, mainly the following: 1, gastrointestinal diseases, is the most common cause, common gastritis, gastric ulcer, digestive tract obstruction and poor gastric power, etc., can take oral drugs to promote gastrointestinal power, as well as gastric mucosa protective drugs for symptomatic treatment, appropriate activities to promote gastrointestinal power. 2, liver and biliary diseases, common liver function abnormalities, inflammation of the gallbladder or bile duct stones and other diseases, often accompanied by right upper abdominal pain, especially aggravated after eating. If you have chronic pancreatitis, there will be a significant loss of appetite and abdominal pain. 4. symptoms. You can get a clear diagnosis based on your symptoms and related tests and then treat the symptoms.