Retrograde bacterial infections are predominantly found in women (male: female about 1:8) among outpatients with urinary tract infections. This is because the female urethra is shorter (about 3-4 cm) and the opening is quite close to the vagina and anus, so bacteria can easily enter the urinary system and cause infections due to poor hygiene habits or sexual behavior. The following is an introduction to the prevention of retrograde bacterial infections. 1, drink more water. Drinking more water can flush the urethra and eliminate urethral bacteria. Likewise, you can drink drinks rich in vitamin C. Vitamin C increases the acidity of urine and reduces bacterial production. 2, do not hold urine. Holding urine often will stimulate the bladder, making it unbearable and causing painful and urgent urination. 3, appropriate exercise. Sitting for a long time is easy to make the body worse, the bladder tolerance becomes worse, should do appropriate exercise to improve the body’s immune system. 4, pay attention to personal hygiene. Summer and the turn of summer and autumn are sweaty season, wear loose clothing to prevent bacterial growth, but also pay attention to skin cleanliness.