What causes urinary tract infections?

Dear Doctor,

I’m in my 30s and fairly healthy. However, I keep getting urinary tract infections. My husband and I want to know what I can do to prevent them.


Dear Dina,

For various reasons, urinary tract infections (UTIs) are very common in young women. First is the short length of the urethra (tube connecting bladder to the exterior). This facilitates bacteria to easily enter the urinary bladder. Another is the dampness in the pelvic region during menstrual periods. Bacteria can enter the genitals and pass on to the urinary bladder during sexual activity. Poor personal hygiene, dirty undergarments, nylon under garments, all these increase the risk of urinary tract infections. Any trauma to the bladder during child birth also makes it more accessible to microbes. Any instrumentation in the bladder, like a catheter, can introduce germs as well. Drinking inadequate amounts of water helps to build up concentration of microbes in the urine, causing UTIs. It can occur due to any sexually transmitted disease or pelvic infections, due to the close proximity of the bladder to the genitals.

Among other conditions, uncontrolled diabetes increases the risk for repeated urinary tract infection. Conditions of reduced immunity like HIV infection, enhances the possibility of UTI in presence of other risk factors. Increased pH of the vaginal flora increases susceptibility to infections and can cause recurrent UTI.

 Mostly, it is due to bacterial infections. After an infection, the body does not develop immunity for viral infections. Therefore if one takes treatment for UTI, the infection present at that time is cured. But if risk factors recur and one is exposed to the infection again, it can recur. One may have infection by microbes that do not respond to antibiotics given.

Prevention of UTI lies in preventing the risk factors. Improving pelvic and menstrual hygiene is very useful in preventing UTI.  A woman should avoid dampness being built up during menses. It is also beneficial to pass urine after sexual intercourse and wash the genitals. Undergarments should always be clean and dry and preferably made of cotton. Fancy nylon undergarments tend to rub the soft skin of private parts and cause abrasions. Another important thing is that one should not hold urine for long when the bladder is full. This also tends to help in increasing concentration of microbes in the bladder. After going to the toilet, the perineum should be cleaned from the front backwards and not vice versa. Otherwise germs from the rectum and anus can contaminate the genitals.

If in spite of these precautions one gets repeated UTI, it is advisable to get a culture of mid-stream sample of urine. This will help in identifying the causative germs and the most suitable antibiotic which will cure it.


Dr. Rachna Pande is a specialist in internal medicine.