Postprandial blood glucose of 19 mmol/L is higher than normal and is usually more serious. The cause of the elevated blood glucose needs to be clarified. It may be caused by hyperthyroidism, gastrojejunostomy, or diabetes mellitus or diabetic ketoacidosis; hyperthyroidism, gastrojejunostomy can be recovered after active treatment of the primary disease, and diabetes mellitus needs to be actively controlled blood glucose level. 1. Hyperthyroidism, gastrojejunostomy: patients with such conditions can generally return to normal after treatment of the primary disease. 2. Diabetes or diabetic ketoacidosis: diabetic patients with 19mmol / L two hours after the meal indicates poor blood sugar control, if long-term poor blood sugar control may induce diabetic nephropathy, cardiovascular disease and other serious complications; diabetic ketoacidosis need to go to the hospital immediately, follow the instructions of the rehydration fluid, insulin injection therapy; such cases are more serious. Postprandial blood glucose 19mmol / L is recommended to go to the hospital, please ask the doctor to make a judgment, should not be blindly judged.