Urinary tract infections are divided into upper and lower urinary tract infections according to the site of infection; they can be divided into isolated or sporadic infections and recurrent infections according to the relationship between the two infections, the latter can be divided into re-infections and bacterial persistence, and bacterial persistence is also known as recurrence; and according to the state of the urinary tract at the onset of the infection, they can be divided into simple urinary tract infections, complicated urinary tract infections and urinary septicemia. Urinary tract infections often occur in women, especially in sexually active and postmenopausal women. 1, immune function: normal immune function is a guarantee of health, it can fight against the environment of the cell decline has an impact on a variety of factors, thus preventing cell aging and maintain cell regeneration. Elderly people’s immune function gradually decline, cellular immune function also declines. With the decline of immune function, the resistance of the elderly to bacterial, viral and fungal infections decreases. 2, nutritional status: the elderly may appear atrophy of the digestive glands, digestive enzyme secretion is reduced. Although the amount of nutrients needed by the elderly is low, the relative lack of vitamins and trace elements can lead to a decline in the body’s resistance and stress capacity. 3, chronic diseases: the incidence of urinary tract infections in the elderly patients with some chronic diseases increased significantly. Various neurological diseases, such as stroke, senile dementia with fecal incontinence to personal hygiene. Diabetic female patients are prone to lower urinary tract infections, and can be secondary to pyelonephritis, which may be associated with abnormal polymorphonuclear leukocyte function, hyperglycemia, repeated episodes of vaginitis, bladder function abnormalities, as well as multiple catheterization and other factors. 4, chronic prostatitis: men’s recurrent urinary tract infections and chronic prostatitis. The infection of prostatitis is not caused by other parts of the body through the bloodstream to reach the prostate, but mainly from the urethral infection or infected urine through the prostate tube back into the prostate and caused. 5, urinary difficulties: common causes are: urethral stenosis, mainly traumatic or gonorrhea urethral stenosis; prostatic hyperplasia or prostate cancer, accounting for about 75% of male urinary tract obstruction; pelvic muscle relaxation caused by uterine prolapse or bladder bulge; bladder polyps and tumors; neurogenic bladder, central nervous system disease, cerebral vascular disease secondary to bladder dysfunction. Urinary tract obstruction and urinary retention are the most common causes of geriatric urinary tract infections.