What Causes a Urinary Tract Infection? 7 Things That May Make a UTI More Likely

Urinary tract infections (UTIs) occur when bacteria get into the urinary system. This includes the kidneys, bladder, urethra, and ureters. The urinary system is usually quite sterile. However, troublesome bacteria, like E. coli can enter and overwhelm the urinary tract. Once inside, these bacteria rapidly multiply, causing a UTI.

Understanding the underlying causes of a UTI is important. It can help you with prevention, treatment, and avoiding serious complications.

What causes UTIs?

There are several risk factors that can increase your likelihood of developing a UTI. Let’s take a closer look at the seven most common causes of a UTI. 

1. Sexual activity

During sexual intercourse, bacteria from the genital and anal areas may be transferred to the urethra. This can lead to an increased risk of UTI. This is much more common in people assigned female at birth.

Women experience UTIs more frequently than men, primarily due to their shorter urethras. This provides easier access for bacteria to enter the bladder.

2. Pregnancy

In pregnancy, hormonal shifts can relax your urinary tract muscles. This can cause urine to accumulate in your bladder for longer periods of time and increase the risk for UTI. Additionally, pregnant people can have immune system changes that lower the body's ability to fight off infections.

3. Birth control

Certain birth control methods can increase your risk for UTI. Diaphragms and spermicides may alter the balance of bacteria in the genital area. This can make it easier for bacteria to enter the urinary tract. 

If you develop a UTI while using a diaphragm, it may not be the right size. Talk with your healthcare provider about your birth control options if you’re having UTIs while using diaphragms or spermicide.

4. Menopause

Estrogen plays an important role in keeping the urinary tract healthy. It helps to support the growth of helpful bacteria to keep harmful bacteria at bay. But a drop in estrogen levels during menopause can allow infectious bacteria to thrive. This can increase your risk of UTIs during menopause.

5. Urinary tract abnormalities

Structural issues in the urinary system can cause UTIs. Anatomic irregularities, present at birth or that develop later in life, can prevent the bladder from emptying properly. Or they can block the regular flow of urine. This can create a favorable environment for bacteria to flourish. And cause you to be at risk for UTIs.

6. Catheter use

The use of catheters, like indwelling urinary catheters, are a common cause of UTIs. Urinary catheters involve the insertion of a flexible tube into the bladder through the urethra. This process can introduce bacteria from the surrounding environment or the genital area into the urinary tract. 

7. Health conditions

Certain medical conditions can make you more prone to developing a UTI, such as:

• Kidney stones: These can cause urinary tract obstructions, making bacterial growth more likely.

• A weakened immune system: Conditions like diabetes, HIV/AIDS, or cancer can weaken the body's natural defense against infections.

• Neurological disorders: Conditions like spinal cord injury, multiple sclerosis, and Parkinson’s disease can increase your risk of UTIs.

• Benign prostatic hyperplasia (BPH): An enlarged prostate puts pressure on the urethra, preventing the bladder from emptying completely. This condition increases bacterial growth in the urinary tract and the risk of UTIs.

Can you prevent UTIs?

Good hygiene and healthy lifestyle choices are important in reducing the risk of UTIs. Here are some strategies to lower the likelihood of developing UTIs:

• Wipe front to back. This can help prevent the transfer of bacteria from the anal area to the urethra.

• Keep hydrated. Not drinking enough water and fluids can lead to concentrated urine. This may potentially irritate the bladder.

• Don’t hold it. Holding your urine for extended periods of time can provide a breeding ground for bacteria in the urinary tract.

• Avoid certain hygiene products. Douches or powders can disrupt the natural balance of bacteria in the genital area and increase your UTI risk.

• Pee after sex. Urinating both before and after sexual intercourse can help flush out any bacteria.

• Consider your options. Women in menopause can reach out to their healthcare provider and talk about vaginal estrogens and other treatment options. 

• Optimize your health. Managing any underlying medical conditions that increase your risk for a UTI can help to prevent them.

When do you need to see a doctor for UTI treatment?

If you’re having UTI symptoms, be sure to contact your healthcare provider for treatment. Treating a UTI involves antibiotics to clear the infection. And it’s important to take all of the antibiotics that your healthcare provider prescribes to make sure the bacteria are completely eliminated.

Remember, alternative remedies like cranberry supplements, probiotics, herbals, and acupuncture are not a substitute for treatment — especially if you have a confirmed UTI.

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Written by:

Bernadette Anderson, MD, MPH

A native of Saginaw, Michigan, Dr. Bernadette earned an undergraduate degree in psychology from the University of Michigan, Ann Arbor. She completed a master's degree in public health at the University of California, Berkeley, and a doctorate of medicine from the Medical College of Ohio.

Edited by:

Karla Robinson, MD

Karla Robinson, MD, is a medical editor for GoodRx. She is a licensed, board-certified family physician with almost 20 years of experience in health through varied clinical, administrative, and educational roles.

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