We often see patients who complain of frequent and painful urination, even with microscopic or visual hematuria. The onset of the disease is rapid, sometimes accompanied by back discomfort and fever. Urinalysis is performed with high levels of white and red blood cells. Blood tests sometimes have elevated white blood cells. Routine ultrasound examination of the kidneys, ureters and bladder shows no positive findings. In this group of patients we will diagnose urinary tract infection and will give oral or intravenous anti-infective treatment. The symptoms usually disappear after 1 to 2 weeks of treatment. Urinary tract infection, also known as urinary tract infection, is a general term for infections in various parts of the urinary system, including the kidneys, ureters, bladder and urethra. There are upper urinary tract infections and lower urinary tract infections. Upper urinary tract refers to the kidney and ureter (pyelonephritis), and lower urinary tract refers to the bladder and urethra (cystitis and urethritis). The pathogenic bacteria are mainly Escherichia coli. The prevalence in women is mainly related to the anatomy of the female urethra. Risk factors are sexual activity or recent sexual intercourse. Decreased estrogen levels are a risk factor for urinary tract infections in postmenopausal women. The vast majority of patients with acute simple cystitis can turn negative for urinary bacteria after treatment with monotherapy or 3-day therapy, but must be rechecked 4-7 days after treatment. Chronic cystitis is treated with effective antibacterial drugs based on urine bacterial culture and drug sensitivity testing. It is important to use the full amount and the full course of treatment. 2~3 antibacterial drugs can be used alternately for more than 2 weeks or longer. Acute pyelonephritis apply effective antimicrobial drugs for 14 days, if there is still bacteriuria after the drug, then the drug should be changed according to the drug sensitivity test and treated for another 6 weeks. Urinary tract infections are prone to reinfection and recurrence, and for such patients a low-dose, long-course antibacterial therapy should be considered as prophylaxis. It is also necessary to perform a complete urinary tract examination to exclude the possibility of uroepithelial tumors. For such patients, we often advise them to drink more water, take rest, not to strain too much, and not to hold urine, which is also crucial to prevent recurrence. “Patients often ask how much water they should drink is enough. Generally, we mainly look at the amount of urine and decide the amount of water to drink. If the urine volume is more than 1500ml per day, we think drinking water should be considered enough.