What causes frequent urinary tract infections?

Urinating is the most basic physiological function. Each person must excrete at least 1 liter of urine every day. The urine above 1 liter is the waste material left after continuous filtration by the body and is excreted through the urinary tract to achieve a metabolic balance inside the body. However, the urinary tract is relatively fragile and can be easily stimulated by external factors and become diseased. For example, why do we often have urinary tract infections?

Urinary tract infection, also known as urinary system infection, is an inflammatory response of the urothelium to bacterial invasion, usually accompanied by bacteriuria and pyuria.

1. More than 95% of urinary tract infections are caused by a single bacteria. Among them, 90% of outpatients and about 50% of inpatients are caused by Escherichia coli, which can be classified into 140 types of serotypes. The urinary infection-causing Escherichia coli is of the same type as the Escherichia coli isolated from the patient's feces, and is often seen in asymptomatic bacteriuria or uncomplicated urinary infection; Proteus, Clostridium difficile, Klebsiella pneumoniae, Pseudomonas aeruginosa, and fecal Streptococcus are seen in patients with reinfection, indwelling catheters, and complicated urinary tract infections; Candida albicans and Cryptococcus neoformans infections are often seen in patients with diabetes and those using glucocorticoids and immunosuppressants and after kidney transplantation; Staphylococcus aureus is often seen in bacteremia and sepsis caused by skin trauma and drug addicts; although viral and mycoplasma infections are rare, they have tended to increase in recent years.

2. Multiple bacterial infections are seen in indwelling catheters, neurogenic bladder, stones, congenital malformations, and vaginal, intestinal, and urethral fistulas.

3. Urinary tract infection is divided into upper urinary tract infection and lower urinary tract infection according to the site of infection; according to the relationship between the two infections, it can be divided into isolated or sporadic infection and recurrent infection, the latter can be divided into reinfection and bacterial persistence, bacterial persistence is also called recurrence; according to the state of the urinary tract at the time of infection, it can be divided into simple urinary tract infection, complicated urinary tract infection and urosepsis. Urinary tract infections are common in women, especially those who are sexually active and postmenopausal women.