Lower urinary tract infections, also commonly referred to as cystitis, are very common in clinical practice. The main manifestations of cystitis are frequent, urgent, painful urination and distension of the lower abdomen, which is often aggravated by touching the lower abdomen with the hand. Generally speaking, the common cause of lower urinary tract infections is due to bacterial infection. The most common clinical pathogen is Escherichia coli, and the infection is usually transmitted retrograde, mainly through the urethra, which infects the bladder mucosa and causes lower urinary tract infections. Clinically, the infection is usually caused when the body’s immune system is low, such as common as tiredness, stay up late. In addition, for female patients in the process of sexual intercourse easily cause damage to the mucosa of the urethra, which can easily cause their resistance to decline, thus making the infection more likely to occur. Therefore, lower urinary tract infections are generally common in adolescent women.