Low pepsinogen type I may be caused by atrophic gastritis, gastric cancer and other diseases, which can be treated with medication and surgery. 1. Atrophic gastritis: pepsinogen type I is secreted by the main cells and mucus cells of the fundic glands, and low pepsinogen type I represents the decline of secretion function of gastric mucosa. When there are long-term use of acid-suppressing drugs, chronic gastritis and other triggers, the decline in gastric mucosal secretion function may lead to atrophic gastritis. You can take medicines to protect gastric mucosa such as bismuth potassium citrate and colloidal bismuth pectin, and avoid taking medicines to inhibit gastric acid secretion such as omeprazole and ranitidine. 2. Gastric cancer: When gastric cancer occurs, the morphology of gastric mucosa changes and loses its normal function, which leads to the decrease of gastric acid secretion and low pepsinogen I. There is no specific treatment drug for gastric cancer. There is no specific treatment drug for gastric cancer, and tumor resection or total gastrectomy is usually needed. When low pepsinogen type I appears in the examination, it is not recommended to take medication by oneself, and it is recommended to take further examination such as gastroscopy and pathological biopsy to find out the cause of the disease, and then use medication and treatment under the guidance of doctor.