Encyclopedia / U / Urinary Tract Infection (UTI, Cystitis)

Urinary Tract Infection (UTI, Cystitis)

What Is A Urinary Tract Infection?

A urinary tract infection (UTI), also referred to as a bladder infection or cystitis, occurs when bacteria enter the urinary tract and travel into the urethra to the bladder. A UTI is a common infection seen 10 times more often in women than in men. A kidney infection, also called pyelonephritis, occurs when the infection travels up into the kidneys. Pyelonephritis is less common than bladder infections but tends to be more serious.

Who Gets Urinary Tract Infection?

Approximately 50% of women will have one UTI or more in a lifetime. There is also a high recurrence rate, approaching 30-40% within six months to a year. UTIs are one of the most common causes of physician visits. The fact that women have a shorter urethra compared with men may play a role on why the condition is seen more frequently in women.


  • Burning sensation during urination.
  • Pain during urination.
  • Frequent urination.
  • Urination in small amounts.
  • Urgent need to urinate or lack of urinary control.
  • Blood in the urine.
  • Lower abdominal pressure or pain.
  • Painful sexual intercourse.
  • Chills, fever, back pain (pylonephritis)

Causes/Risk Factors

  • About 75 % to 95% of UTIs are caused by the bacteria E. coli, which normally inhabits the colon and the anal area with no ill effect; however, if bacteria enter the urinary tract, infection may ensue.

Factors that increase the risk of UTIs include:

  • Having diabetes.
  • Use of a spemicidal agent for birth control.
  • Previous bladder or kidney infection.
  • Use of a urinary catheter may introduce bacteria to the bladder.
  • Sexual activity.
  • Sexual activity with a new partner.
  • Obstruction of urine flow by a bladder tumor or, in men, an enlarged prostate may lead to bladder infection.
  • Pregnancy also increases the risk of UTIs as the growing fetus compresses the bladder so that it doesn’t empty completely, allowing bacteria to be static and to reproduce.
  • Some cases of recurring UTIs are due to structural abnormalities that impede the flow of urine.
  • Some women with recurrent disease may be genetically predisposed.

What If You Do Nothing?

Mild cases of cystitis and urethritis may often clear up without treatment. But if symptoms last longer than two days or worsen, you should consult a doctor, since some untreated UTIs may turn into kidney infections, which can be longer and harder to cure.


  • Patient history/symptoms and physical examination.
  • Urinalysis and, occasionally, culture of a urine sample for bacteria in a doctor’s office. (Most urine cultures take 48 hours for results.)


  • Your doctor may prescribe an oral antibiotic to fight the infection. The infection may improve within days, but you should take the antibiotic for the full term prescribed. (Antibiotics are typically given for three to seven days.)
  • You may also be given antispasmodics and analgesics to relieve the pain. A heating pad can help relieve discomfort.
  • Drink plenty of liquids.
  • Drink cranberry juice to increase the acidity of the urine, as some medicines are more effective with acidic urine.
  • Kidney infection may require a long-term course of antibiotics (up to six weeks) and, in severe cases, hospitalization with intravenous medication.


  • The use of spermicides and diaphragms may predispose women to urinary tract infections by altering vaginal bacteria, which may spread to the urethra.
  • Urinate when you feel the urge (retaining a full bladder promotes infection).
  • Women with serious or recurrent UTIs associated with intercourse should ask their doctor about taking preventive antibacterial medications on a daily basis.
  • Urinate after sexual activity.
  • Menopausal women may be helped by using estrogen vaginal cream.
  • Research has not shown that douching or the direction of wiping after toilet use prevents UTIs.

When To Call Your Doctor

  • Call your doctor if you experience symptoms of a UTI, especially if they are accompanied by a high fever or if symptoms recur or persist despite treatment.
  • Call your doctor if you develop pain in the lower back, which may indicate a kidney infection. Bacteria from the UTI may have migrated to the kidney.

Reviewed by Thomas Moran, M.D., obstetrician-gynecologist in private practice, Springfield, MA.