The reasons for sleeping thirsty at night are as follows: suffering from immune system diseases, such as dry syndrome, the volume of salivary glands atrophy, the secretion of saliva is greatly reduced, and you will feel the dryness and burning sensation of oral mucosa at night when you sleep, and you must drink a lot of water to relieve it. The metabolic level of the body of diabetic patients is high, and they tend to drink and urinate more, and often feel thirsty. After strenuous exercise during the day, too much sweat is secreted and the body loses a lot of water, which can cause thirst at night. Pregnant women who are breastfeeding will experience thirst at night due to the secretion of milk.