All About Urinary Tract Infections: Causes, Symptoms, and Diagnosis
Physical Health
Urinary tract infections (UTIs) are a common infection — about half of all women will get a UTI at least once in their life. If you’ve ever experienced the urgency, burning, and pain that often comes along with a UTI, you know how uncomfortable it can be.
This article will go over everything you need to know about the causes, symptoms, and diagnosis of UTIs. If you’re curious about how UTIs are treated, check out my article, “How to Treat UTIs”.
What Is a UTI?
A UTI is an infection of part of your urinary tract. UTIs can go by other names, such as bladder infection or cystitis.
UTIs can occur when bacteria infect any part of your urinary tract, including:
- Kidneys — bean-shaped organs that filter waste and excess fluid from your blood to make urine
- Ureters — thin tubes that carry urine from your kidneys to your bladder
- Bladder — a balloon-shaped organ that holds your urine until you’re ready to urinate (pee)
- Urethra — a tube that connects your bladder to the outside of your body
While bacteria and other germs live all over your body, including your skin and gut, bacteria shouldn’t be in your urine or urinary tract. When bacteria invade your urinary tract, it causes an infection that can make you sick and cause unpleasant symptoms.
Types of UTI
Your healthcare provider can classify a UTI in several different ways based on the location of the infection, the cause, or other medical conditions you have.
The medical term for a UTI is different based on the location of your infection. If you have an infection in your urethra, it’s called urethritis. An infection in your bladder is called cystitis. An infection in your kidneys is called pyelonephritis.
UTIs can also be described as simple or complicated. A UTI is considered simple when it occurs in an otherwise healthy person with no differences in their urinary tract. Most of the time, women who aren’t pregnant have simple UTIs.
A UTI is considered complicated if there is an increased risk of complications during treatment. Most UTIs in men and children are considered complicated. A UTI may be considered complicated if it occurs in the following groups of people:
- Men
- Children
- Pregnant women
- People with abnormalities of the urinary tract
- People with a urinary catheter
- People with kidney disease
- People with a medical condition that suppresses the immune system
What Causes a UTI?
Most of the time, UTIs are caused by a bacteria called Escherichia coli (E. coli). In fact, E. coli is responsible for more than 90% of all UTIs. Other types of bacteria can also cause a UTI but E. coli is usually the cause.
Normally, E. coli is found in your intestines (gut) and around your anus. If E. coli or other bacteria are introduced to part of your urinary tract, they can cause an infection. Examples of ways this can happen include wiping from back to front after using the bathroom or during sex.
Your body does have ways to help protect against infection. Your urine can actually help flush out bacteria that do make it into your urethra. Urine only flows in one direction — from your kidneys, to your bladder, and through your urethra. Because of this, any bacteria that make it into your bladder will be flushed out when you pee. However, this defense can fail and result in a UTI.
How Common Are UTIs?
UTIs are very common. It’s estimated that between 8 million and 10 million people are treated for a UTI every year. Women are about four times more likely to develop a UTI compared to men.
It’s estimated that between 40% and 60% of women will have a UTI at some point in their life. Of women who develop UTIs, about 1 in 4 of them will have another UTI (recurrent UTI).
Compared to other types of UTIs, cystitis is the most common.
Why Are Women More Likely To Get a UTI?
Women are more likely to get a UTI, mostly due to differences in their anatomy. Compared to men, women have a shorter urethra. This means that bacteria don’t have to travel as far to reach the bladder. Additionally, the opening of a woman's urethra is closer to the anus, where E. coli and other bacteria can be found.
Women may be more susceptible to UTIs at certain periods of their lives. When a woman is pregnant, increased pressure on the urinary tract may increase the likelihood of developing a UTI. Changes in hormones after menopause can also make women more likely to develop a UTI. Menopause refers to hormonal changes that occur in middle-aged women when the menstrual period ends. These hormone-related changes during and after menopause can affect how well the vagina is able to protect against infection.
What Are the Risk Factors for Developing a UTI?
Anyone can get a UTI, but you may be more likely to develop a UTI if you have certain risk factors, including:
- Having sex
- Using a diaphragm or spermicide for birth control
- Have a urinary catheter (a tube inserted through your urethra that helps empty your bladder into a drainage bag)
- Have had UTIs in the past
Your risk of developing a UTI may be higher if you have any of the following medical conditions:
- Have a spinal cord injury or nerve damage around your bladder that makes it difficult to completely empty your bladder
- Kidney stones
- Enlarged prostate
- Physical abnormality of your urinary tract
- Diabetes
- Suppressed immune system
Talk to your healthcare provider about your risk for developing a UTI.
What Are the Symptoms of a UTI?
When bacteria infect part of your urinary tract, it causes inflammation. This inflammation is what causes the symptoms of a UTI, such as:
- Burning or pain when you pee (dysuria)
- Frequent or urgent urge to pee, even if you just went
- Pressure in your pelvis
- Pain in your sides, stomach, pelvis or back
- Inability to hold your pee (urinary incontinence)
- Blood in your pee (hematuria)
- Pee that looks cloudy
- Pee that smells bad
When you have a UTI, you may also experience symptoms that affect your whole body, including:
- Extreme tiredness (fatigue)
- Fever and chills
- Nausea or vomiting
- Confusion
Symptoms of a UTI that affect your whole body can be serious. If you experience these symptoms, you should contact your healthcare provider right away and seek immediate medical care.
What Are the Complications of UTI?
If you get proper treatment for a UTI, your risk of UTI complications is low. However, complications can occur, such as:
- Recurrent UTIs (when you have 2 or more UTIs within 6 months or 3 or more UTIs in 1 year)
- Kidney damage from a kidney infection that may be permanent
- Narrowing of the urethra in men
- Sepsis (a life-threatening extreme reaction to an infection)
If you’re diagnosed with a UTI, talk to your healthcare provider about how to prevent complications.
How Is a UTI Diagnosed?
You should seek medical treatment if you notice symptoms of a UTI. To help diagnose a UTI, your healthcare provider will ask you questions about how you’re feeling and your medical history. Your provider will also conduct a physical exam and order tests to help confirm a UTI diagnosis.
Laboratory Tests for UTI
A laboratory test is a procedure where a substance from your body (such as blood or urine) is sent to a laboratory for further testing. To test for a UTI, your healthcare provider may ask you to pee in a special cup for a urinalysis and urine culture.
Urinalysis
A urinalysis is a urine test that can help diagnose a UTI. In a urinalysis, your urine will be examined for three aspects:
- How your urine looks (the color and appearance)
- The chemicals and substances found in your urine
- The presence or absence of blood cells and bacteria
If you have a UTI, the first thing your healthcare provider may notice is that your urine appears cloudy.
Further testing may show that you have chemicals called nitrites in your urine. Nitrites are chemicals made by bacteria. You will only have nitrite-positive urine if you have a UTI.
A urinalysis will also test for the presence of white blood cells (also called leukocytes) in your urine. Leukocytes are immune cells that help fight against infection. If you have a UTI, your body’s natural response is to send bacteria-fighting leukocytes to the site of the infection.
Your provider can check if you have leukocytes in your urine by testing for a substance made called leukocyte esterase. Leukocyte esterase is usually only present in your urine if you have an infection.
A small sample of your urine may also be examined under a microscope to check for bacteria and white blood cells. Even though your provider may be able to see bacteria in your urine, this test can’t identify the specific type of bacteria causing your UTI. To find out which bacteria is responsible for your infection, you need a urine culture.
Urine Culture
A urine culture is a test that helps identify the bacteria causing a UTI. If bacteria do grow from your urine sample, the laboratory can use the bacteria to perform an antibiotic sensitivity test. This test checks which antibiotics will kill the bacteria and which antibiotics the bacteria may be resistant to.
To collect a urine sample for a urine culture, you have to make sure the sample isn’t contaminated with other bacteria, such as the bacteria that normally live on your skin. To do this, follow the instructions your healthcare provider gives you. Usually, you will use an antiseptic wipe to clean the area around your urethra before you urinate. Then, you will let out a small amount of urine and stop midstream to flush out any bacteria. After you do this, you can place the urine sample collection cup into your urine stream. To avoid contamination, you should be careful not to touch the collection cup to your skin.
Imaging Tests for UTI
If your UTI doesn’t respond to antibiotic treatment or if your UTI keeps coming back, your healthcare provider may order additional testing to help diagnose the cause of your symptoms. Imaging tests can help diagnose the problem by providing an image of the inside of your body.
Imaging tests for UTI diagnosis may include:
- Ultrasound — a test that uses soundwaves to create a real-time image of your bladder and internal organs
- Computed tomography (CT) scan — a test that combines a series of X-rays and computer technology to create a 3-dimensional image of your organs
- Cystoscopy — a test where your provider inserts a thin, flexible tube with a light and a camera (called a cystoscopy) through your urethra to see inside your bladder
How Should You Prepare for a Healthcare Appointment for a UTI?
If you have symptoms of a UTI or are worried you may have a UTI, you should contact your healthcare provider as soon as possible. Proper diagnosis and treatment for a UTI can help prevent future complications.
A UTI can be diagnosed and treated by your physician or at an urgent care clinic. A little preparation before your appointment for a UTI can help your healthcare provider better diagnose and treat your UTI. Before your appointment, consider the following to get ready:
- Write down any new or unusual symptoms, even if you’re not sure they’re related to a UTI
- Make a list of all medications you take — including prescriptions, over-the-counter medications, vitamins, and supplements
- Make a list of any questions you have for your provider
