Urinary Tract Infection

Español: Infección de las vías urinarias


Urinary tract infections (UTIs) are among the most common infections in people, and antibiotic treatment is usually helpful in treating an infection. Your healthcare professional will be able to determine if you or your child has a UTI and what antibiotic is needed.


UTIs occur when bacteria enter and infect the urinary tract. UTIs can affect several parts of the urinary tract, but the most common type of UTI is a bladder infection (also known as cystitis).

The body can sometimes fight the bacteria without any problems; however, the infection can cause discomfort and may sometimes spread to the kidneys. Kidney infections, also known as pyelonephritis, are less common but more serious.

Risk Factors

Some people have a higher risk of getting a UTI. Women and girls are at a higher risk compared to men and boys because their urethra is shorter and closer to the anus, which makes it easier for bacteria to enter the urinary tract. Other things that can increase your risk for a UTI include:

  • A previous UTI
  • Sexual activity, and especially a new sexual partner
  • Changes in vaginal flora or acidity caused by menopause or use of spermacides
  • Pregnancy
  • Age (older adults are more likely to get UTIs)
  • Reduced mobility (e.g. after surgery or prolonged bedrest)
  • Urinary incontinence or urinary catheter placement
  • Kidney stones
  • Prostate enlargement

In young children, there can sometimes be a structural problem in the urinary tract that can lead to more frequent UTIs. Other factors that increase the risk of UTIs in children include not urinating often enough or wiping from back to front after a bowel movement (in girls this may cause bacteria to enter the urinary tract).

Anatomy of the urinary tract, showing how bacteria can cause an infection.

Urinary tract infections happen when bacteria, often from the skin or rectum, travel up the urethra and into the bladder.

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Signs and Symptoms

Common symptoms for a bladder infection include:

  • Pain or burning while urinating
  • Frequent urination
  • Feeling the need to urinate despite having an empty bladder
  • Low fever (less than 101 °F)
  • Cloudy or bloody urine
  • Pressure or cramping in the groin or lower abdomen

Kidney infections are less common but more serious. Warning signs for a kidney infection include flank or lower back pain, high fever (101 °F or above), nausea or vomiting, mental status changes, chills, or night sweats.

Younger children may not be able to tell you about symptoms that they are having; things to look out for include:

  • Fever of unknown cause
  • Change in urine smell or color
  • Vomiting
  • Fussiness or changes in appetite

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When to Seek Medical Care

If you have any of the symptoms of a UTI listed above, it is appropriate to see your healthcare professional. Contact your healthcare professional right away if you have symptoms of a kidney infection.

Diagnosis and Treatment

Your healthcare professional can do a number of things to determine if you have a UTI, including asking about symptoms, doing a physical examination, and ordering urine tests.

Most UTIs are caused by bacteria and can be treated with antibiotics. However, bacteria are becoming increasingly resistant to antibiotics, which mean common antibiotics may not get rid of infections caused by these resistant germs. Each time you or your child takes an antibiotic, the bacteria that normally live in your body (like those in your intestine) are more likely to become resistant to antibiotics. This is a serious and increasingly common problem since UTIs often recur in the same people.

Sometimes UTI symptoms can be caused by other illnesses, such as sexually transmitted diseases. Other times bacteria can be present in the urine without causing an infection (this is known as asymptomatic bacteriuriaExternal). If your symptoms are caused by a different illness, a different treatment may be necessary.

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Symptom Relief

If you are prescribed antibiotics, take them exactly how your healthcare professional recommends. Never skip doses. Talk with your doctor if you have any questions about your antibiotics. Drink plenty of water to help clear the bacteria from your body.

Some healthcare professionals may also recommend a medicine, such as phenazopyridineExternal, to help lessen the pain or discomfort caused by urinating. If you take this medicine, it is important to continue taking your antibiotics at the same time. This medicine only relieves pain and does not cure the infection.


Changing personal hygiene habits can help prevent recurrent UTIs. Here are some general suggestions:

  • Urinate before and after sexual activity
  • Stay well-hydrated and urinate regularly
  • Take showers instead of baths
  • Minimize douching, and sprays or powders in the genital area
  • When potty training girls, teach them to wipe front to back

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