The hunger when waking up from a nap is usually due to hyperthyroidism, diabetes or indigestion, as follows: 1. Hyperthyroidism: Patients suffering from hyperthyroidism secrete more thyroid hormones and consume protein, sugar, fat and other nutrients at a faster metabolic rate, and will soon be prone to hunger, and patients will generally have symptoms of mental exuberance and physical wasting. 2. The main symptoms of diabetes are three more and one less, that is, eating more, drinking more, urinating more and losing weight. 3, indigestion: the digestive function of the spleen and stomach is reduced, and the food eaten cannot be digested and absorbed in time, so the nutrients in the body are not replenished, so you will feel hungry just after eating. The common diseases are gastritis, gastric ulcer, duodenal ulcer, etc.