Gastritis is known to cause loss of appetite. Gastritis can be categorized into acute gastritis and chronic gastritis. Chronic gastritis can affect the patient’s digestive function, resulting in decreased secretion of digestive juices, decreased smooth muscle tone of the gastrointestinal tract and decreased activity of digestive enzymes, which can cause a loss of appetite and other symptoms such as nausea and abdominal discomfort. Acute gastritis can be limited or widespread acute inflammation of the gastric mucosa, which can cause an imbalance in the regulation of digestive function, leading to loss of appetite, but also epigastric fullness, belching, nausea, vomiting and other symptoms. Patients with loss of appetite or suspected clinical manifestations of gastritis should go to the hospital and ask the doctor to make a judgment and clarify the cause of the disease.