What are recurrent UTIs, and more importantly, why do they happen?

The problem with recurrent UTIs

A recurrent UTI, also called a chronic UTI, is an infection that keeps coming back, even after treatment with antibiotics. These infections can happen 2 or 3 times per year, once every other month, once per month or even multiple times per month. This can be endlessly frustrating for the person on the receiving end of these repeat infections, as they mean more painful UTIs, more visits to the doctor's office, and more cycles of antibiotics.

If the individual continues to experience recurrent UTIs, their doctor might put them on prophylactic antibiotics, which means the constant use of antibiotics just to prevent an infection from happening. Antibiotic resistance puts those with recurrent UTIs at serious risk. The more frequently an individual takes antibiotics for an infection, the more likely it is bacteria will develop resistance to those antibiotics, which makes it less likely that treatment will be effective the next time around. This makes it very important that specific antibiotics are used to treat recurrent UTIs. It has become more and more apparent that bacteria are in a constant arms race with not only antibiotics but our immune system as well.

What puts people at risk for recurrent UTIs, and why can they happen? Some reasons are physical, behavioral, or age-related, but as we’ll learn, running into the wrong type of bacteria can make all the difference in developing a recurrent UTI.


The Bacterial Arms Race 

Recent research has shown that strategies bacteria use to avoid our immune system and our antibiotics may be the main cause of recurrent UTIs. 90% of Urinary Tract Infections are caused by the bacteria E. coli. Yet, there are many different types of E. coli, and some are better equipped at dodging the immune system than others. 

What makes some of them so much worse than others is the ability to lay dormant, and survive long periods of time inside our own cells. These bacteria get inside cells in the urinary tract and create what is called a ‘biofilm’, a protected cluster that is safe from our immune cells and even from antibiotics. These bacteria can survive through a cycle of antibiotics, and once complete when the immune system is weakened the bacteria can grow and re-establish an infection.

New research has also shown that inflammation and damage to cells during an infection can weaken the outer protective cells and make you more susceptible to a subsequent infection, leading to recurrent UTIs if the protective mucosal layer is not able to be repaired before being exposed to more bacteria.

In a recent review entitled Urinary Tract Infections: Epidemiology, Mechanisms of Infection and Treatment Options, the authors detail the risks of continuing to use antibiotics as a treatment method for recurrent UTIs noting “Moreover, high rates of recurrent UTIs suggest that antibiotics are not an effective therapy for all UTIs."

bacteria in the urinary tract

The way our bodies are built can put some women at higher risk of recurrent UTIs. UTIs are much more common in women than in men as a result of physical difference. For example, women’s urethras are shorter than men’s, and the urinary tract opening is positioned more closely to the rectum. Both of these differences make it easier for bacteria to establish themselves in the urinary tract. 

These same factors play a role in the likelihood of some women getting UTIs more easily than others. If a woman’s urethra is particularly short, she can be at higher risk of urinary and bladder infections. In addition, bacteria are often flushed out by the flow of urine. If the urethra is particularly wide or the muscles surrounding the bladder are weak, the flow of urine can be light, making it easier for bacteria to hold on to the urinary tract wall.


Certain behaviors put an individual at risk of developing a urinary tract infection. That means that repeating those behaviors can lead to frequent or recurrent UTIs developing. These behaviors can include not urinating after sexual activity, not drinking enough water, wearing undergarments that don’t breathe well, prolonged physical activity, and long periods without a shower.

Age and Menopause

As women age, they become more at risk of recurrent UTIs. There are 3 main reasons.

  1. With growing age, the immune system weakens, making women more vulnerable to not just UTIs, but all infections.
  2. Menopause causes significant changes in the hormones of aging women. This can affect the makeup of vaginal bacteria, which can protect the urinary tract by making it more difficult for dangerous bacteria to infect the vagina and travel to the urinary tract where they can cause an infection.
  3. The muscles around the bladder responsible for emptying the bladder of urine weaken as we age. This leads to incontinence, or an inability to properly empty the bladder, as well as a lessened urinary flow. Incontinence puts women at increased risk of UTIs as urine isn’t cleared from the bladder.

Recurrent UTIs impact us all differently