A urinary tract infection (UTI) is an infection in any part of your urinary system — your kidneys, ureters, bladder and urethra. Most infections involve the lower urinary tract — the bladder and the urethra.
Women are at greater risk of developing a UTI than men are. Infection limited to your bladder can be painful and annoying. However, serious consequences can occur if a UTI spreads to your kidneys.
Antibiotics are the typical treatment for a UTI. But you can take steps to reduce your chance of getting a UTI in the first place.
Urinary tract infections don't always cause signs and symptoms, but when they do they may include:
- A strong, persistent urge to urinate
- A burning sensation when urinating
- Passing frequent, small amounts of urine
- Urine that appears cloudy
- Urine that appears red, bright pink or cola-colored — a sign of blood in the urine
- Strong-smelling urine
- Pelvic pain, in women
- Rectal pain, in men
UTIs may be overlooked or mistaken for other conditions in older adults.
Types of urinary tract infection
- Upper back and side (flank) pain
- High fever
- Shaking and chills
- Pelvic pressure
- Lower abdomen discomfort
- Frequent, painful urination
- Blood in urine
- Burning with urination
When to see a doctor
See your primary care doctor if you have signs and symptoms of a UTI.
Urinary tract infections typically occur when bacteria enter the urinary tract through the urethra and begin to multiply in the bladder. Although the urinary system is designed to keep out such microscopic invaders, these defenses sometimes fail. When that happens, bacteria may take hold and grow into a full-blown infection in the urinary tract.
The most common UTIs occur mainly in women and affect the bladder and urethra.
- Infection of the bladder (cystitis). This type of UTI is usually caused by Escherichia coli (E. coli), a type of bacteria commonly found in the gastrointestinal (GI) tract. Sexual intercourse may lead to cystitis, but you don't have to be sexually active to develop it. All women are at risk of cystitis because of their anatomy — specifically, the short distance from the urethra to the anus and the urethral opening to the bladder.
- Infection of the urethra (urethritis). This type of UTI can occur when GI bacteria spread from the anus to the urethra. Also, because the female urethra is close to the vagina, sexually transmitted infections, such as herpes, gonorrhea and chlamydia, can cause urethritis.
Risk factors for urinary tract infections include:
- Being female. UTIs are common in women, and many women experience more than one infection. Women have a shorter urethra than men do, which cuts down on the distance that bacteria must travel to reach a woman's bladder.
- Being sexually active. Sexually active women tend to have more UTIs than do women who aren't sexually active.
- Using certain types of birth control. Women who use diaphragms for birth control also may be at higher risk, as may women who use spermicidal agents.
- Completing menopause. After menopause, UTIs may become more common because the lack of estrogen causes changes in the urinary tract that make it more vulnerable to infection.
- Having urinary tract abnormalities. Babies born with urinary tract abnormalities that don't allow urine to leave the body normally or cause urine to back up in the urethra have an increased risk of UTIs.
- Having blockages in the urinary tract. Kidney stones or an enlarged prostate can trap urine in the bladder and increase the risk of UTI.
- Having a suppressed immune system. Diabetes and other diseases that impair the immune system — the body's defense against germs — can increase the risk of UTIs.
- Using a catheter to urinate. People who can't urinate on their own and use a tube (catheter) to urinate have an increased risk of UTIs. This may include people who are hospitalized, people with neurological problems that make it difficult to control their ability to urinate and people who are paralyzed.
When treated promptly and properly, lower urinary tract infections rarely lead to complications. But left untreated, a urinary tract infection can have serious consequences.
Complications of UTIs may include:
- Recurrent infections, especially in women who experience three or more UTIs
- Permanent kidney damage from an acute or chronic kidney infection (pyelonephritis) due to an untreated UTI, especially in young children
- Increased risk of women delivering low birth weight or premature infants
Make an appointment with your primary care doctor if you have symptoms and signs. After an initial evaluation, your doctor may refer you to a doctor who specializes in urinary disorders (urologist) or kidney disorders (nephrologist), especially if you have frequent recurrences or a chronic kidney infection.
What you can do
Tests and procedures used to diagnose urinary tract infections include:
- Analyzing a urine sample. Your doctor may ask for a urine sample for lab analysis to look for white blood cells, red blood cells or bacteria. To avoid potential contamination of the sample, you will need to collect the urine midstream.
- Growing urinary tract bacteria in a lab. Lab analysis of the urine is often followed by a urine culture — a test that uses your urine sample to grow bacteria in a lab. This test tells your doctor what bacteria are causing your infection and which medications will be most effective.
- Creating images of your urinary tract. If your doctor suspects that an abnormality in your urinary tract causes frequent infections, you may have a computerized tomography (CT) scan to create images of your urinary tract. In certain situations, your doctor may also use a contrast dye to highlight structures in your urinary tract. Another test, called an intravenous pyelogram (IVP), uses X-rays with contrast dye to create images. Historically, doctors used this test for urinary tract imaging, but it's being replaced more often by CT scan.
- Using a scope to see inside your bladder. If you have recurrent UTIs, your doctor may perform a cystoscopy, using a long, thin tube with a lens (cystoscope) to see inside your urethra and bladder. The cystoscope is inserted in your urethra and passed through to your bladder.
Doctors typically use antibiotics to treat urinary tract infections. Which drugs are prescribed and for how long depend on your health condition and the type of bacterium found in your urine.
Drugs commonly recommended for simple UTIs include:
- Sulfamethoxazole-trimethoprim (Bactrim, Septra, others)
- Amoxicillin (Amoxil, Augmentin, others)
- Ciprofloxacin (Cipro)
- Levofloxacin (Levaquin)
Usually, symptoms clear up within a few days of treatment. But you may need to continue antibiotics for a week or more. Take the entire course of antibiotics prescribed by your doctor to ensure that the infection is completely gone.
Your doctor may also prescribe a pain medication (analgesic) that numbs your bladder and urethra to relieve burning while urinating. One common side effect of urinary tract analgesics is discolored urine — orange or red.
There's some indication, though it hasn't been proved, that cranberry juice may have infection-fighting properties and drinking it daily may help prevent urinary tract infections. Studies have shown the greatest effect in women who have frequent UTIs. Studies involving children and older adults have had mixed results.
It's not clear how much cranberry juice you'd need to drink or how often you'd need to drink it to have an effect. If you enjoy drinking cranberry juice and feel it helps you prevent UTIs, there's little harm in continuing to drink it, but watch the calories.
Urinary tract infections can be painful, but you can take steps to ease your discomfort until antibiotics clear the infection. Follow these tips:
- Drink plenty of water to dilute your urine and help flush out bacteria.
- Avoid drinks that may irritate your bladder. Avoid coffee, alcohol, and soft drinks containing citrus juices and caffeine until your infection has cleared. They can irritate your bladder and tend to aggravate your frequent or urgent need to urinate.
- Use a heating pad. Apply a warm, but not hot, heating pad to your abdomen to minimize bladder pressure or discomfort.
Take these steps to reduce your risk of urinary tract infections:
- Drink plenty of liquids, especially water. Drinking water helps dilute your urine and ensures that you'll urinate more frequently — allowing bacteria to be flushed from your urinary tract before an infection can begin.
- Wipe from front to back. Doing so after urinating and after a bowel movement helps prevent bacteria in the anal region from spreading to the vagina and urethra.
- Empty your bladder soon after intercourse. Also, drink a full glass of water to help flush bacteria.
- Avoid potentially irritating feminine products. Using deodorant sprays or other feminine products, such as douches and powders, in the genital area can irritate the urethra.