Must know: 25 main UTI causes

Main UTI Causes. What makes you prone to UTIs?

In order to prevent urinary tract infections, you must know the main UTI causes.

Many think that poor hygiene is the main reason for UTI, but this is far from the truth. In most cases, your hygiene habits have little to do with your chances to develop a UTI. Surprisingly, if you are a woman, the secret to a UTI-free life could be in your vagina. And if you keep experiencing persistent chronic UTIs, bacterial biofilms might be the one to blame.

To make it a little easier, I grouped UTI causes in 5 main “buckets” to help you to remember what to watch out for. Altogether, there are 26 main reasons discussed in this article, the list is still far from being complete. Since chronic and recurrent UTI is a systemic problem, many things could contribute to your UTI susceptibility, but this post is a good start to examine your risk factors.

Misbalanced Vaginal Flora

Compromised vaginal flora is one of the most overlooked UTI causes. There is a very close link between loss of normal vaginal flora (particularly, Lactobacillus species) and an increased risk of contracting a UTI.

“Wait a second,” I hear you saying, “if UTIs happen in my bladder, what does my vagina have to do with it?”.

Unfortunately, the important role of a healthy vagina in UTI prevention is not common knowledge. The fact is E.coli bacteria (that cause 90% of all UTIs and live in your lower intestines) ascend from your anal region toward your urethra. On the way toward your urethra pathogenic bacteria pass through your vagina. If your vaginal flora is healthy, the bad guys will struggle to survive. However, if vaginal flora is compromised, E.coli bacteria will multiply and continue climbing up toward your urethra and eventually, the bladder.

A healthy vaginal flora consists of predominantly Lactobacillus species. Those tiny good bacteria are on your side. Every day researchers find more and more ways that these beneficial bacteria help our bodies to function and how the lack of those bacteria could lead to various misalignments.

For example, scientists speculate that:

  • Lactobacillus species might help to maintain the low pH of the genital area
  • Produce hydrogen peroxide
  • Hinder the growth of E. coli
  • Help to down-regulate inflammatory reactions caused by E. coli.

In plain words, not only do good bacteria make it hard for E. coli bacteria to grow and populate your genitals, but they also reduce inflammation and support healthy pH of your vagina.

However, it is easy to affect the wellbeing of your well-meaning bacteria. Those tiny warriors are kind of fragile and plenty of things can disrupt their ability to grow and protect you.

Here are are some factors that can affect your vaginal flora and therefore could be considered risk factors for UTI.

1. Condoms with spermicide

The most popular spermicide used for condoms is Nonoxynol-9. This chemical is known to disrupt your vaginal flora and to suppress the growth of beneficial Lactobacilli.

No wonder many think that condoms cause a UTI, when in fact it’s the spermicide that works against you. If you can, use condoms without spermicide to avoid this UTI risk-factor.

2. Other Nonoxynol-9 contraceptives

Plenty of other contraceptive products use Nonoxynol-9 such as contraceptive film, sponges, suppositories, creams, and tablets. You want to avoid these as much as you can. If in doubt, make sure to read the label.

3. Lubricants

I used to get a yeast infection every time after using a lubricant. And no wonder, lubricants can also be a contributing factor of UTI causes.

Avoid lubricants that have Glycerin or Sorbitol on their ingredient list since these tend to feed your pathogenic bacteria and yeast, which then suppress the growth of the protective Lactobacilli.

4. Antibiotics

Antibiotics are supposed to cure, not cause a UTI, right? That’s true, they will help you to get rid of acute infection but in doing so could handicap your own natural defenses.

You see, when an antibiotic is busy killing E.coli and other bad bacteria that caused your UTI, your good bacteria also suffer. As you can expect, you find yourself in a vicious cycle: you need antibiotics to fight an acute infection, but after the fight is over your vagina is no longer protected against pathogenic bacteria. That’s why ladies who suffer from recurrent UTIs could be most vulnerable to contract a UTI again within a week after antibiotic treatment.

5. Stress

This factor seems to affect all aspects of our health. Whatever health problem you have, more often than not you can link some of them to stress. Not only do you feel nervous and anxious but your bacteria suffer too.

Apparently, some studies show that stress decreases the number of Lactobacillus species that live and prosper in your body (as reported by Femke Lutgendorff et al. in the June 2008 issue of Current Molecular Medicine). Take a deep breath and make yourself a chamomile tea, go for a walk and count your blessings. More importantly, include special probiotics in your diet so you can lend a helping hand to your Lactobacilli population.

6. Diet

Apparently, your friendly bacteria are picky eaters. Also, they like healthy food and lots of fiber. They also need a variety of fiber so drinking lots of psyllium husk won’t be enough. Stock up on various veggies and fruits, exclude processed food and sugars and add a nice prebiotic blend to your diet.

7. Lack of estrogen

Women don’t have it easy: periods, cramps, UTIs, babies, and menopause! Menopause frequently comes with an increased risk of UTI due to lack of estrogen that in turn, disbalances their vaginal flora. On top of this, the lack of estrogen leads to thinning of the protective layer of the vaginal walls. It makes it easier for pathogenic bacteria to hide in the vagina.

Of course, change in your hormones could happen at any age, but chances are higher that you’ll need estrogen supplementation once you are older.

Studies show that when women are given estrogen hormones their vaginal Lactobacillus flora increased and therefore, hormonal changes could be counted as one of the important UTI causes.

Increased number of opportunistic bacteria

More than 80% of all UTIs in the world are caused by opportunistic bacteria, such as Escherichia coli bacteria (E. coli) that reside in your own gut. Therefore, we can speculate that higher E. coli concentration can lead to increased chances of contracting a UTI.

8. Constipation

Constipation is not only unpleasant but it is also a symptom of a bigger problem. The thing is, your gut is similar to your vagina and is also populated by millions of bacteria.

Your body needs these bacteria to aid in various important functions such as the breakdown of food into absorbable nutrients, the stimulation of the host immune system to prevent the growth of pathogenic bacteria and to produce a great variety of biologically important compounds. For example, E. coli bacteria when contained in the lower gut are helpful in producing vitamin K.

However, constipation could be a sign of an alteration in your microbiome. Some bacteria species reduce their activity, while others continue to strive. Unfortunately, the bacteria that continue to grow are mostly the ones that could become pathogenic if they get into your urethra.

So constipation is a risk factor for UTI because it could increase the number of bad bacteria in your stool and therefore around your anus. On top of this, constipation might also cause internal pressure on your bladder, obstructing it and making it more difficult to empty the bladder completely.

Bottom line, eat your veggies and exercise to prevent UTIs caused by constipation.

9. Dehydration

Unless this is your very first UTI, you must have heard a million times that it is important to stay hydrated to prevent urinary tract infections. Why? Well, gone are days when scientists thought that your bladder is sterile. It is not. As everywhere else, there are dozens of various strains of bacteria in your bladder doing whatever they need to do to keep you healthy. However, pathogenic bacteria enter your bladder from time to time as well. All those bacteria live their busy lives and multiply.

If there is no fresh urine that washes through your bladder frequently, the old urine harbors growing pathogenic bacteria and this could cause a UTI.

10. Vesicoenteric fistulae

In some rare cases, bacteria could be leaking from your gut straight into your bladder. This condition is known as Vesicoenteric fistulae (or enterovesical or intestinovesical fistulae).  This is literally an opening between the bowel and the bladder that could happen as a result of a surgery, accident, cancer, or abnormal anatomic development of an embryo. Most frequently, however, due to physiological differences, this is observed in men rather than in women.

Bladder obstruction

Inability to fully void your bladder is one of the main reasons for UTIs. As described above, when old urine remains in your bladder, it allows bacteria to grow. Anything that causes urine to stay in the bladder for a prolonged period of time can increase your chances of developing a UTI.

Evidently, anyone with an abnormality of the urinary tract that obstructs the flow of urine—a kidney stone or enlarged prostate, for example—is at risk for a UTI.

Therefore, these are five UTI causes related to bladder obstruction:

11. Spinal cord injuries or other nerve damage around the bladder

Spinal cord injuries can be of varying degrees. In some cases, an injury can result in a decreased ability to feel the urge to urinate, leaving urine in the bladder for too long. Other patients might not be able to initiate the urination on their own at need a catheter to empty the bladder which might also lead to urine staying in the bladder for longer periods of time.

12. Kidney and bladder stones

Stones not only obstruct normal urine flow but also damage protective bladder lining allowing for pathogenic bacteria to hide and prosper, causing recurrent UTIs. On top of that, bacteria are able to create their own colonies on the surface of the stones, called biofilms that are often impossible to eradicate with antibiotics.

13. Anatomic abnormalities

Some folks are born with a deformity that could actually make urine flow backward (aka Vesicoureteral reflux (VUR). If a child is diagnosed with recurrent UTIs, the doctors would most likely check with ultrasound equipment if their kidneys function well.

14. Bladder and urethra scarring, blood clots

The more infections you experience, the higher are your chances to develop bladder lining abnormalities. Anything but perfectly healthy bladder lining could be a cause for recurring UTIs by providing hiding places for pathogenic bacteria and allowing for so-called embedded UTI. A bladder lining that went through numerous UTIs will be eroded and lack its protective qualities that’s why healing your bladder is an important step in UTI preventive strategy. 

15. Enlarged prostate

This is the only factor that is unique to guys. The prostate is located in close proximity to the urethra and if enlarged could make it hard or even impossible to pee. If you can’t pee out your old urine, you are just asking for trouble. Moreover, if the prostate is infected by E.coli bacteria they can eventually reach your bladder and cause a bloodborne UTI.

16. Weak bladder muscles

In this case, a patient can’t squeeze his or her bladder muscles strong enough to empty the bladder completely, constantly leaving old urine in the bladder. There are non-invasive tests, such as uroflowmetry, that your doctor can perform to assess the strength of your bladder muscles.  

Bladder flora

Decreased number of good bacteria in your bladder is one of the reasons bad bacteria can grow faster. As we discussed earlier, your bladder is not sterile. Certain microbes including beneficial ones exist in the healthy human bladder.

Multiple factors including diet and even your blood type can affect your bladder flora making it more or less prone to urinary tract infections.

These factors include:

17. Chronic diseases (for example, diabetes)

If you have diabetes, you are twice as likely to contract a urinary tract infection (UTI). Extra glucose in your urine drives changes in your bladder flora making you more prone to UTIs. However, diabetes is not the only culprit. Any chronic inflammation or suppressed immune system, allergies, chronic digestion issues could contribute to your overall ability to fight infections.

18. Surgeries

Certain types of surgeries, for example, TransVaginal Mesh can be a risk factor for UTI. Any bladder surgery messes up your natural bladder microbiome and could potentially result in a UTI.

19. Use of instrumentation and catheters

Catheters are a known culprit of UTIs. Think of it as a bridge and also a hiding place for pathogenic bacteria in your bladder. What’s more, any use of instrumentation or catheters can scratch the gentle inner surface of the urethra and bladder. Even a catheter that was used temporarily during a surgery or a procedure (intermittent catheter) can damage urethral or bladder lining and make it easier for bacteria to hide and proliferate.

20. Antibiotics

Similar to how antibiotics affect your vaginal microbiome, they influence the bacterial composition of your bladder microbiome as well.

21. Bacterial Biofilms

One could argue that bacterial biofilms in the bladder are the number one reason for chronic recurrent urinary tract infections. These are bacterial colonies that attach themselves to the bladder surface and produce protective slime to avoid antibiotics and immune system defenses. Pathogenic bacteria hide under the slime of a biofilm and are dormant during the treatment but wake up and grow after the treatment is over. If you notice that your symptoms subside during antibiotic treatment, but a week or two later you have an infection again, this could be due to bacterial biofilms.


Activities that transfer bacteria

In some cases, your hygiene routines can pose a greater UTI risk. I’m sure if you are an adult, you are wiping from front to back. Should we even talk about it? Nonetheless, if you ever go to a physician’s office you are destined to hear it again.

But besides wiping there are other activities that can help your E. coli bacteria to “get a lift” from your anus towards your urethra and will increase the chances of contracting a UTI.

22. Bad hygiene

Take your shower, do not sleep in the same underwear that you wear all day. Oh, and, of course, wipe from front to back.

Bad hygiene also means over-cleaning. Using antibacterials soaps, vaginal douching and too frequent washing could alter your genital skin microbiome.

23. Sex

If your vaginal flora is compromised, E. coli can grow in your vagina. The next time you have sex the bacteria will get much closer to your urethra, greatly increasing your chances of a UTI. Sex on its own doesn’t cause a UTI but it’s a major risk factor if your vaginal flora is compromised.

24. Thongs

A narrow piece of material will pick up more bacteria and then slide back and forth while you move. While studies did not find conclusive evidence, many doctors recommend opting for simple cotton panties instead of thongs.

25. Feminine menstrual products

Just remember to change them regularly or they could become a breeding ground for pathogenic bacteria. Blood is alkaline and your Lactobacilli prefer an acidic environment. So do not put too much stress on your vaginal flora and change pads and tampons as frequently as possible.

26. Anal sex

On its own, anal sex or finger anal play would not cause a UTI. However, as you know, E.coli live in your lower intestines and these activities bring the bacteria from inside to the surface of your anal region. To be safe, use a condom and discard it right away. Do not use the same condom for vaginal penetration.

Am I missing anything? Leave me a comment below and share your thoughts.


Next: read how to Prevent UTI: Myths and Facts