The cause of thirst in the middle of the night every day may be diabetes, urolithiasis, central system disorders, or discomfort caused by recent diet. Diabetic patients may experience excessive drinking early in the disease; urolithiasis patients show excessive urination, and the basis for the appearance of excessive urination is drinking more water, and their desire to drink at night is also strong. The desire to drink is most likely not because the body is dehydrated and wants to rehydrate, but the most direct cause may be a problem in the central system that sends the wrong signal to the body, causing the body to mistakenly think it wants to drink, even at night. In addition to these more serious diseases, eating spicy food for several days in a row will leave the body in a dry, dehydrated state, and the body will continuously stimulate the central system to send out instructions in order to maintain a good water content, and thirst will also occur in the middle of the night.