Causes of urinary tract infection: 1. personal factors, such as failure to pay attention to personal hygiene, failure to wash in a timely manner or exposure to contaminants, etc. 2. decreased function of the autoimmune system, if combined with other systemic infections, weakness after various surgeries, combined with diabetes or infection of peripheral organs, such as gynecological inflammation spreading to the urinary system and infection, etc. 3. increased virulence of local bacteria, such as bacterial multiplication in the acute phase or colonization of the urinary system. 4. Combined with urinary system malformation or other obstructive lesions. If there is a combination of stones, the stones can cause mucosal damage and urinary tract infections. If there is a combination of prostatic hyperplasia, the difficulty in urination leads to an increase in residual urine in the bladder, resulting in recurrent urinary tract infections over time. Injuries to the urinary system after various surgeries or catheterization operations, for example, can lead to exogenous urinary tract infections.