Urine fire is a folk saying, mainly refers to the burning sensation in the urethra, accompanied by a series of uncomfortable symptoms such as frequent urination, urinary urgency, urinary pain, etc. It can be seen in the physiological causes, but also common in the urinary tract infection. 1. Physiological causes: such as in overwork, drinking a lot of alcohol, as well as eating too much spicy and stimulating food, usually after rest, drink more water, light diet, the body can self-regulate. 2. Urinary tract infection: When urinary tract infection occurs, bacteria multiply in the urethra, which can irritate the mucous membrane of the urethra, causing a burning sensation, and in severe cases, there may be difficulty in urination, or even the symptom of urinary retention. When the burning discomfort of urination occurs, it is recommended to consult a doctor in time.