Urinary tract infections

Overview

When Your Body's Natural Filter Falters

Your urinary tract is your body's filtering system for liquid wastes. When you're healthy, the urine is sterile. But when infectious organisms invade, you end up with a urinary tract infection (UTI). UTIs are usually caused by bacteria, although they can also be caused by viruses, fungi, or a variety of parasites. The telltale signs of a UTI are the urgent and frequent need to urinate; you may also notice pain or burning when you urinate and cloudy or bloody urine. Sexually active women are especially vulnerable to UTIs because of the close proximity of the urethra — the short tube that urine passes through on its way out of the body — to the vagina and rectum.

While urinary tract infections can be quite painful, they are easily treated in most cases. Once he or she diagnoses a UTI, your doctor will usually prescribe antibiotics that can relieve your symptoms in 24 to 48 hours.

Detailed Description

The urinary tract in is divided into a lower part and an upper part. The upper part of the tract consists of the kidneys, which make urine from the blood that circulates through its filtering and collecting systems, and tubes called ureters that carry urine to the bladder. An infection of the upper tract causes more severe illness than an infection of the lower tract, but it's also less frequent.

The lower part is made up of the urethra, a 1-1/2- to 2-inch-long tube that urine passes through on its way out of the body, and the bladder, which stores urine. Most infections occur in the lower part and although they are very uncomfortable, they are seldom serious.

The organisms that cause infection usually enter the urinary tract one of two ways: at the end of the urinary tract (the urethra) or at the beginning (the kidneys). Most often, infectious organisms enter the urinary tract through the urethra by going in the opening at the tip of a man's penis or the opening of a woman's urethra (or within the vulva). More than 85% of UTIs are caused by bacteria from a person's own intestine or vagina. Sometimes though, the infection enters the urinary tract through the bloodstream, in these cases usually directly to the kidneys.

Urinary tract infections cause pain and burning during urination; they also make you feel the urgent need to urinate often. Other symptoms may include a mild fever and chills. Women are more prone to UTIs because of their anatomy: a woman's urethra is shorter than a man's and is very close to the vagina and rectum.

A midstream (or clean-catch) urine specimen is usually used to detect a UTI and a course of antibiotics can cure it, but recurrent infections may necessitate further testing and daily doses of antibiotics taken regularly, or perhaps only after sex.

How Common Are Urinary Tract Infections?

Urinary tract infections are more common in male than female newborns, but by age 1, they are about 10 times more common in girls. However, the great increase begins after initiating sexual intercourse. Therefore, UTIs in young girls are a clue for sexual abuse.

Although both men and women commonly get UTIs, between the ages of 20 and 50, women are 50 times more likely to contract one than men. According to the American College of Obstetricians and Gynecologists, doctors diagnose approximately 5 million cases of urinary tract infection in women ever year. And, about one of every five women will have a UTI in her lifetime.

UTIs become more common in both men and women with a smaller gap in incidence between the sexes as they age.

What You Can Expect

If you suspect you have a urinary tract infection, see your doctor. He or she will ask you to urinate in a cup so he can do a urinalysis, which involves examining the urine specimen using chemical analyses and under a microscope. He or she may also do a pelvic exam because UTIs and vaginal infections often occur simultaneously. If you test positive for a UTI, you will probably be given a prescription for antibiotics. About a week after you finish the treatment, your doctor may ask you for another urine sample to be sure the infection has been cured. Urinary tract infections are very treatable; you should feel better within 48 hours of beginning antibiotic treatment. However, be sure to finish all the antibiotics you are prescribed.

Conventional Treatment

Goals of Treatment

Identifying and killing the bacteria causing the infection and your discomfort is your medical caregiver's goal when treating a UTI.

Your doctor will prescribe an antibiotic that you will probably have to take for seven to 10 days, but sometimes only one dose is needed. Even if your symptoms disappear, be sure to follow your doctor's directions and finish your entire prescription. If you stop early, the infection may still exist and resurface.

Urinary tract infections can usually be easily cured if diagnosed early and treated promptly with an effective antibiotic.

Appropriate Health Setting

Most urinary tract infections are treated with oral antibiotics on an outpatient basis.

Healthcare Professionals Who May Be Involved in Treatment

Some healthcare professionals who may be involved in managing or treating your infection include:

  • Gynecologists
  • Internists
  • Family practitioners
  • Urologists
  • Nurse practitioners
  • Emergency medicine physicians

Activity and Diet Recommendations

At the first sign of a UTI, start drinking more water and cranberry juice (which contains hippuric acid, which seems to help prevent infection). Urinary flow helps keep the urinary tract clean (this phenomenon is called the "washout effect").

Drug Therapy

Pain Relief

Your doctor may prescribe a urinary analgesic to provide relief from the pain, burning, urgency, and frequency of urination associated with UTIs. This analgesic is generically called phenazopyridine hydrochloride, and is sold under many brand names.

Antiobiotics

Your doctor will probably prescribe one of the following antiobiotics to treat your UTI:

Amoxicillin
http://www.nmihi.com/a/amoxicillin.html

On-Label Efficacy

Augmentin
http://www.nmihi.com/c/co-amoxiclav.html

On-Label Efficacy

Cipro
http://www.nmihi.com/c/ciprofloxacin.html

On-Label Efficacy

Bactrim
http://www.nmihi.com/t/co-trimoxazole.html

On-Label Efficacy

Keflex

On-Label Efficacy

Levaquin
http://www.nmihi.com/l/levofloxacin.html

On-Label Efficacy

Ampicillin

On-Label Efficacy

Suprax (cefixime)

On-Label Efficacy

Ceclor (cefaclor)

On-Label Efficacy

Ceftin (cefuroxime)

On-Label Efficacy

Vibramycin (doxycycline)

On-Label Efficacy

Surgery

Uncommonly, surgery may be necessary to relieve a physical obstruction to urine flow, such as a stone, or to correct a structural abnormality, such as a drooping uterus and bladder. In rare cases, surgery may be necessary to drain a renal abscess.

Monitoring the Condition

It is important that you finish the entire course of prescribed antibiotic to avoid recurrent infection with more virulent bacteria.

Your doctor may ask for another urine sample about a week after you finish your treatment to make sure the infection has been cured.

Some women are particularly prone to repeated bouts of infection. If you suffer from recurrent urinary tract infections, your doctor may prescribe low-dose antiobiotics as a preventive measure, or perhaps after sex, if that causes the problem.

Quality of Life

Recurrent UTIs can be quite frustrating. Talk to your doctor about what you can do to help minimize the risk of contracting infections.

Considerations for Women

Pregnancy

UTIs are one of the most common complications of pregnancy. Pregnant women are more prone to urinary tract infections because hormonal changes cause dilation of the ureters and because of the pressure the baby puts on the bladder. As many as one-third of pregnant women with untreated bacteria in the urine will develop kidney infection by the third trimester, though they may not exhibit any symptoms. Because this puts the mother at risk for early labor and premature delivery, many doctors search for these asymptomatic UTIs in pregnant women and treat them whether or not the infection is causing the woman any discomfort.

Penicillins and cephalosporins are the preferred drug therapy since they are generally considered safe during pregnancy (although they're also less effective than other antiobiotic choices).

Considerations for Children and Adolescents

Recurrent infections in children may suggest an anatomical abnormality in the urinary tract, or sexual abuse.

Considerations for Older People

Infections in older people may have more serious consequences, including incontinence.

Self care & Prevention

Preventing Urinary Tract Infections

If you are particularly prone to urinary tract infections (and even if you aren't), here are some suggestions to help prevent future occurrences:

  • Urinate regularly (every two to three hours), and empty your bladder completely each time. When you feel the urge, go. Women with recurrent UTIs tend to hold their urine for extended periods. If you are prone to UTIs, go every two hours, even if you don't feel the urge.
  • Drink plenty of fluids to help flush out your bladder.
  • Always wipe from front to back after urinating or after a bowel movement to prevent spread of bacteria from the rectum to the urethra and vulva.
  • Wash the genital area each time you bathe or shower.
  • Urinate before and after intercourse to help flush out bacteria.
  • Practice safe sex. Nothing that touches your anal area should come in contact with your vagina.
  • Wear cotton underwear — it breathes better than synthetics.
  • Avoid tight clothes in the genital area such as control-top pantyhose and tight jeans.
  • Avoid sitting around in wet bathing suits.
  • Avoid vaginal deodorants and perfumed deodorant soaps, which are irritating and can increase the risk of UTIs.
  • Spermicides increase the risk of UTIs. You may want to choose alternatives to condoms or a diaphragm, both of which work best in combination with spermicides. Incorrectly sized diaphragms are also a risk factor. Consider other contraceptives, but don't forget to factor your sexual safety into any decision to stop using condoms and/or spermicides.

Self-Care Measures

Once you do become infected, here are some suggestions for minimizing symptoms:

  • Drink six to eight glasses of fluids each day to flush out and clean the bladder
  • Wear cotton underwear and avoid tight clothing
  • Don't use vaginal deodorants, douches, or other potentially irritating substances
  • Heat can be soothing: Try a warm sitz bath, or a heating pad on your lower abdomen
  • Pour warm water over genital area while urinating to relieve burning
  • Cranberry juice and echinacea may be helpful
Urinary tract infections

Last updated 23 May 2012

Synonyms

  • Bladder infection (cystitis)
  • Infection of the urethra (urethritis)
  • Infection of the ureters (ureteritis)
  • Kidney infection (pyelonephritis)

Causes

Established Causes

Eighty-five percent of UTIs are caused by bacteria from a peron's own intestine or vagina. The bacteria may travel up the urethra causing infections in the bladder or elsewhere in the urinary tract. This bacteria is spread by the following:

  • The back and forth motion of the penis during sexual intercourse
  • Not urinating frequently enough (urination serves as a flushing action, washing bacteria from the bladder as it empties)
  • Conditions such as pregnancy and neurological disease, which make it difficult to completely empty your bladder
  • Blockage (e.g., stones) anywhere in the urinary tract
  • Leaking of the valve between the ureter and the bladder (vesico-ureteral reflux), which allows urine to flow backward from the bladder
  • Insertion of a urinary catheter, a small flexible tube
  • A narrowing in one of the tubes in the urinary tract
  • An enlarged prostate gland or other parts of the male reproductive system (seminal vesicles)
  • Small pockets that bulge out of the bladder wall or urethra and hold urine
  • A condition in which the structures that support the bladder weaken, allowing the bladder to protrude into the vagina (cystocele)

Other, less common causes of UTIs include the following:

  • Viruses, such as the herpes simplex virus type 2 (HSV-2)
  • Fungi, such as those that cause yeast infections
  • Parasites, including worms
  • Infection of the bloodstream (septicemia)
  • Infection of the heart valves (infective endocarditis)

Risk Factors

Activities that spread bacteria are the most common risk factors for a UTI, but other factors may contribute as well. The following put you at greater risk for contracting a urinary tract infection:

  • New sexual partner
  • An increase in frequency and vigor of sexual activity (that's why UTIs are sometimes called "honeymoon cystitis")
  • Anal intercourse
  • Massage of the urethra
  • Contraceptive diaphragm use
  • Pregnancy
  • Insertion of a urinary catheter or other instrument by a doctor
  • Infection from other systemic regions (usually from the bloodstream)
  • Underlying structural abnormalities of the urinary tract that impede urine flow
  • Previous urinary tract infections
  • Diabetes mellitus, a disorder in which blood sugar levels are abnormally high
  • Kidney disease
  • Kidney transplant

Symptoms & Diagnosis

Signs and symptoms of urinary tract infections (UTIs) include:

  • Urgent need to urinate
  • Increased urinary frequency (especially at night)
  • Pain or burning during urination (dysuria)
  • Fever
  • Chills
  • Nausea
  • Vomiting
  • Soreness in the lower abdomen, lower back, and/or sides
  • Cloudy urine
  • Blood in urine (this occurs in about 30% of people with UTIs)
  • Pain during sex

But keep in mind that people whose nerves supply to the bladder is malfunctioning (neurogenic bladder), people who have had a catheter left continuously in the bladder, and older people may not show any symptoms.

Conditions That May Be Mistaken for a Urinary Tract Infection

Different diseases that may cause symptoms similar to those of a urinary tract infection (UTI) include:

  • Vaginitis
  • Sexually transmitted diseases (STDs) that cause inflammation or discharge

How Urinary Tract Infections Are Diagnosed

Your doctor will diagnose a UTI by counting the number of white blood cells found in your urine sample. He or she will examine your urine sample under a microscope (to count the bacteria) and culture it in a substance that promotes bacteria growth (to determine what kind of bacteria it is).

Your doctor will probably ask for a clean-catch urine sample so that it is not contaminated with bacteria from the tip of the penis or the vulva. He or she will provide women with premoistened cleaning pads and detailed directions on wiping yourself before you urinate. You'll take the sample midstream: you'll begin urinating into the toilet, move the cup into the stream for a moment, and then move it before you finish urinating. Your doctor may also do a pelvic exam to search for a vaginal infection.

Home Tests

There are also several do-it-yourself tests on the market, which may be especially helpful for women who suffer from recurrent infections since the earlier you detect the infection the easier it is to treat and the less discomfort you suffer.

Clinical Tests

If you've had several UTIs or even a single kidney infection, your doctor may refer you to a doctor who specializes in disorders of the urinary tract, called a urologist. The urologist may perform the following tests to determine whether any abnormalities in your urinary tract are the cause of the infections:

  • Cystoscopy: This test examines the urethra and the interior of the bladder. During the exam, a slender metal tube with a light (cystoscope) is inserted through the urethra into the bladder. The cystoscope then removes urine and small bits of tissue for further testing.
  • Cystourethrography: The purpose of this test is to determine whether any urine is traveling backward (reflux) instead of down and out of the urinary tract. This test is similar to IVP. During the test, a chemical is inserted into a woman's bladder and X-rays are taken as she urinates.
  • Intravenous pyelography (IVP): This test involves injecting a chemical that shows up in X-rays into the body. If there is a blockage in the kidneys, ureters, and bladder, the chemical will cause it to appear in the X-ray film.
  • Magnetic resonance imaging and computed tomography: Magnetic resonance imaging (MRI) and computed tomography (CT) scans use X-rays to generate almost three-dimensional pictures of your urinary tract. These tests are not painful (except for the insertion of an IV), and you will reman conscious for the entire procedure.

Alternative care

Herbs

  • Cranberry juice: cranberries have an age-old folk reputation as a treatment for urinary problems. In 1984, researchers discovered that commercial cranberry juice keeps UTI-causing bacteria from attaching to the bladder wall. Boston researchers gave 153 women either a placebo or a cup of cranberry juice a day. Six months later, the cranberry group developed half as many UTIs.
  • Echinacea: try adding it to your cranberry juice. Echinacea stimulates the immune system, which can help your body combat the bacteria in your bladder. Take one teaspoon of tincture three times a day in your cranberry juice. (Echinacea may cause temporary tingling or numbing of the tongue. This is effect is harmless.)