Common Causes and Risk Factors for Urinary Tract Infections

Woman rushing to bathroom with urgency holding her hands to her crotch.
  • A urinary tract infection (UTI) is a bacterial infection that can affect anyone. It can cause discomfort ranging from mild to very painful.

  • UTIs are caused by a number of factors. Factors such as gender and age determine what the potential risks for you may be.

  • Understanding and identifying the causes of a UTI can help to prevent infection and recurrence.

What is a UTI?

A urinary tract infection (UTI) is a bacterial infection of the kidneys, ureters, bladder, and urethra. It is possible for men, women, older people, and children alike to have a UTI. Women, especially those who are sexually active, are the most prone.

Common Causes of UTIs

There are various factors that could cause a urinary tract infection. It is important to understand the causes of UTIs to learn how to prevent them in the future.

Bacterial infections

The most common cause of a UTI is a bacterial infection.

Escherichia coli (E. coli) is the source of urinary tract infections about 90% of the time. This bacteria lives in the intestinal tract, but when it makes its way into the urinary tract, it causes an uncomfortable and often painful infection.

Risk Factors for UTIs

There are various ways in which bacteria can enter the urinary tract, some of which include:

  • Having sexual intercourse
  • Using certain contraceptive methods (such as diaphragms or spermicide)
  • Wiping from back to front after a bowel movement
  • Having kidney stones
  • Ignoring the urge to urinate or not emptying the bladder completely
  • Using a urinary catheter
  • Having a weakened immune system
  • Being dehydrated or not drinking enough water while exercising

These factors contribute to UTI development because they enable bacterial growth throughout the urinary tract. It is important to seek medical attention if you suspect you may have a UTI. Infections that go untreated can travel from the urinary tract to the kidneys, which can lead to more serious issues.

UTI Causes in Women

Because women have a shorter urethra than men, bacteria near the vagina can find its way into the urethra more easily, causing a UTI.

Can sexual activity cause UTIs?

Engaging in sexual activity increases the chances of urinary tract infections. During sex, bacteria from the rectum can be carried into the urethra, and increased friction to the area can further irritate it.

Substances like saliva, sperm, and lubricants won’t directly cause a urinary tract infection. In some cases, though, they may inflame the vaginal walls or urethra. Any inflammation to the urethra can make it vulnerable to invasive bacteria.

Can contraceptives cause UTIs?

It’s important to practice safe sex practices to help protect your body against STDs. Condoms can considerably reduce the chance of UTIs in most women, as they prevent bacteria from entering the urinary tract.

Contraceptives like spermicide and diaphragms can increase the risk of urinary tract infections in women.

Spermicide condoms increase irritation in the vaginal walls, facilitating the development of bacteria. An active ingredient in spermicide called Nonoxynol-9 represses the “good bacteria'' found in the vagina. E. coli may develop and grow in the vagina while its defenses are limited before moving into the urethra.

Diaphragms can obstruct the urethra, leaving small amounts of urine in the bladder, which allows bacteria to collect.

UTI causes during pregnancy

Pregnant women are at a higher risk of developing a UTI because of the many changes to their immune and urinary systems. Babies can also add extra pressure to the bladder as they grow. This pressure can cause a blockage in the bladder, reducing the flow of urine to the urethra.

Pregnant woman in bathroom holding her stomach.

Yeast infections and UTIs

Yeast infections cannot cause urinary tract infections, just as UTIs cannot cause yeast infections. Although these two infections may have similar causes and their symptoms can result in comparable symptoms, yeast infections are caused by unwanted fungi, not bacteria.

It is possible — though unlikely — to have a yeast infection and a UTI at the same time. In addition, taking antibiotics for a urinary tract infection can lead to a yeast infection. Since antibiotics kill a wide range of bacteria, they also can eliminate the healthy bacteria that prevent overgrowth of yeast, which may result in infection.

Think you may have a UTI or yeast infection? Not sure which one? Head over to LifeMD to talk to a licensed healthcare professional from the comfort of your home — or anywhere you are.

UTI Causes in Men

Urinary tract infections are not very common in men, but they do occur. Some of the main causes of infection in men include:

STIs and UTIs in men

Sexually transmitted infections can also lead to UTIs in men. Chlamydia, gonorrhea, and syphilis are all bacterial infections that can affect urinary tract health. When left untreated, the infections may worsen and cause secondary infections to the prostate gland, making urination extremely painful.

UTI Causes in Children

UTIs in children tend to be more commonly caused by issues with the urinary tract’s development, or improper hygienic practices. Girls and uncircumcised boys have a higher risk of infection.

Toilet hygiene

For children, learning proper toilet hygiene is key to maintaining a healthy urinary system and avoiding infections. Reminding children to use the bathroom as soon as they feel the urge, encouraging them to drink lots of water and healthy fluids, and keeping their bottom clean and dry are essential factors in avoiding UTIs.

For young girls, wiping from front to back can reduce the risk of urinary tract infections. This technique limits bacteria from fecal matter from entering the urethra.

Kid sitting on toilet and holding toilet paper.

Anatomical abnormalities

Vesicoureteral reflux (VUR) is a condition in which urine moves backwards through the urinary tract toward the ureters and kidneys. This issue most occurs in very young children with an abnormal ureter. Antibiotics are sometimes prescribed to treat infections caused by VUR.

Though genetic, VUR usually resolves on its own as the child gets older. In very rare cases, though, surgery may be required to repair an abnormal ureter or remove the source of the blockage.


Constipation is a frequent cause of urinary tract infections in children. When stool fills the colon and rectum, it can put pressure on the bladder. This alone can cause infection, but it can also prevent the bladder from emptying completely. Urine that becomes stagnant in the bladder can become infected.

Constipation can also cause UTIs in adults, but it is not very likely.

Prompt treatment

Monitoring your children’s bathroom hygiene can help to ensure prevention of UTIs and prompt treatment if an infection is present. If left untreated, urinary tract infections can lead to greater issues in the kidneys.

UTI Causes in Older People

Urinary tract infections in older people tend to be caused by issues of incontinence or the use of a bladder catheter. As we age, our immune system – along with the bladder muscles and pelvic floor – slowly weaken, which can lead to urine retention or incontinence. Any time urine remains in the urinary tract, there is a possibility of infection.

CAUTIs – or UTIs caused by catheters — occur through the introduction of the device to the urinary tract. Prolonged periods of time in which catheters are inside the body predispose patients to bacteria. CAUTIs are the most common type of urinary tract infection in seniors.

Other Contributing Factors

In general, having a weakened or compromised immune system may increase your risk of developing an infection. People with diabetes are at a higher risk of developing a UTI.

If you are taking certain medications, your chances of contracting a urinary tract infection may be higher. Talk to your doctor about the side effects of your medications to understand if you are at risk of infection.

It is also important to remember that stress can increase your chances of developing a UTI. Stress leads to high levels of cortisol, which weakens the immune system and makes you more susceptible to a UTI.

Dehydration can also cause a urinary tract infection. Remember to drink plenty of water throughout the day, especially on hotter days or when you are exercising. Water helps to flush out harmful toxins and infections in the urinary tract.

When Should I See a Doctor for My UTI?

When left untreated, UTIs can cause damage to the kidneys, which may lead to more serious issues. If you are someone who may be at risk of complications from a urinary tract infection, it is important to seek medical attention as soon as you suspect you have one.

With LifeMD, you can get a UTI diagnosis online and have antibiotics ordered to your local pharmacy – all without having to step foot in a doctor’s office.

Where Can I Learn More About UTIs?

Although UTIs can be easily treated, there are many steps you can take to help avoid them altogether. Drinking plenty of water, avoiding irritants, and practicing good toilet hygiene are all great preventive methods.

With LifeMD, you can learn more about common UTI symptoms and find the most effective treatment for you. If you’re concerned about a possible UTI, be sure to seek advice from a licensed medical professional. Head over to LifeMD to make a video appointment today.

Dina Whiteaker, APRN

Dina earned her MSN from the University of Nebraska Medical Center before becoming a Family Nurse Practitioner. She has 10ᐩ years of telemedicine experience. Dina is board certified and is a member of the American Academy of Nurse Practitioners.

Talk To A Doctor

LifeMD makes it easy to stay on top of your health because talking to a doctor, filling your prescriptions, getting your labs done—and more—are all easy and cost-effective. Come discover a healthcare solution built around you and your life.

Connect with a doctor now!

This article is intended for informational purposes only and should not be considered medical advice. Consult a healthcare professional or call a doctor in the case of a medical emergency.

Feel better with LifeMD.

Your doctor is online and ready to see you.

Join LifeMD today and experience amazing healthcare, discounted labs and prescription medications... plus around-the-clock access to medical guidance.