Urinary Tract Infection Symptoms, Causes and Treatments

A urinary tract infection (UTI) is an infection involving the kidneys, ureters, bladder, or urethra. These are the structures that urine passes through before being eliminated from the body. Continue...
 

• The kidneys are a pair of small organs that lie on either side of the spine at about waist level. They have several important functions in the body, including removing waste and excess water from the blood and eliminating them as urine. These functions make them important in the regulation of blood pressure. Kidneys are also very sensitive to changes in blood sugar levels and blood pressure and electrolyte balance. Both diabetes and hypertension can cause damage to these organs.
• Two ureters, narrow tubes about 10 inches long, drain urine from each kidney into the bladder.
• The bladder is a small saclike organ that collects and stores urine. When the urine reaches a certain level in the bladder, we experience the sensation that we have to void, then the muscle lining the bladder can be voluntarily contracted to expel the urine.
• The urethra is a small tube connecting the bladder with the outside of the body. A muscle called the urinary sphincter, located at the junction of the bladder and the urethra, must relax at the same time the bladder contracts to expel urine.

Any part of this system can become infected. As a rule, the farther up in the urinary tract the infection is located, the more serious it is.

• The upper urinary tract is composed of the kidneys and ureters. Infection in the upper urinary tract generally affects the kidneys (pyelonephritis), which can cause fever, chills, nausea, vomiting, and other severe symptoms.
• The lower urinary tract consists of the bladder and the urethra. Infection in the lower urinary tract can affect the urethra (urethritis) or the bladder (cystitis).
• In the United States, urinary tract infections account for more than 7 million visits to medical offices and hospitals each year.
  
• Urinary tract infections are much more common in adults than in children, but about 1%-2% of children do get urinary tract infections. Urinary tract infections in children are more likely to be serious than those in adults (especially in younger children).
• Urinary tract infection is the most common urinary tract problem in children besides bedwetting.
• Urinary tract infection is second only to respiratory infection as the most common type of infection.
• These infections are much more common in girls and women than in boys and men younger than 50 years of age. The reason for this is not well understood, but anatomic differences between the genders (a shorter urethra in women) might be partially responsible.
• About 40% of women and 12% of men have a urinary tract infection at some time in their life.

 

What causes a urinary tract infection?

The urine is normally sterile. An infection occurs when bacteria get into the urine and begin to grow. The infection usually starts at the opening of the urethra where the urine leaves the body and moves upward into the urinary tract.

• The culprit in at least 90% of uncomplicated infections is a type of bacteria called Escherichia coli, better know as E. coli. These bacteria normally live in the bowel (colon) and around the anus.
• These bacteria can move from the area around the anus to the opening of the urethra. The two most common causes of this are improper wiping and sexual intercourse.
• Usually, the act of emptying the bladder (urinating) flushes the bacteria out of the urethra. If there are too many bacteria, urinating may not stop their spread.
• The bacteria can travel up the urethra to the bladder, where they can grow and cause an infection.
• The infection can spread further as the bacteria move up from the bladder via the ureters.
• If they reach the kidney, they can cause a kidney infection (pyelonephritis), which can become a very serious condition if not treated promptly.

The following people are at increased risk of urinary tract infection:

• People with conditions that block (obstruct) the urinary tract, such as kidney stones
• People with medical conditions that cause incomplete bladder emptying (for example, spinal cord injury or bladder decompensation after menopause)
• People with suppressed immune systems: Examples of situations in which the immune system is suppressed are HIV/AIDS and diabetes. People who take immunosuppressant medications such as chemotherapy for cancer also are at increased risk.
• Women who are sexually active: Sexual intercourse can introduce larger numbers of bacteria into the bladder. Urinating after intercourse seems to decrease the likelihood of developing a urinary tract infection.
• Women who use a diaphragm for birth control
• Men with an enlarged prostate: Prostatitis or obstruction of the urethra by an enlarged prostate can lead to incomplete bladder emptying, thus increasing the risk of infection. This is most common in older men.
• Males are also less likely to develop UTIs because their urethra (tube from the bladder) is longer. There is a drier environment where a man's urethra meets the outside world, and fluid produced in the prostate can fight bacteria.
• Breastfeeding has been found to decrease the risk for urinary tract infections in children.

The following special groups may be at increased risk of urinary tract infection:

• Very young infants: Bacteria gain entry to the urinary tract via the bloodstream from other sites in the body.
• Young children: Young children have trouble wiping themselves and washing their hands well after a bowel movement. Poor hygiene has been linked to an increased frequency of urinary tract infections.
• Children of all ages: Urinary tract infection in children can be (but is not always) a sign of an abnormality in the urinary tract, usually a partial blockage. An example is a condition in which urine moves backward from the bladder up the ureters (vesicoureteral reflux).
• Hospitalized patients or nursing-home residents: Many of these individuals are catheterized for long periods and are thus vulnerable to infection of the urinary tract. Catheterization means that a thin tube (catheter) is placed in the urethra to drain urine from the bladder. This is done for people who have problems urinating or cannot reach a toilet to urinate on their own.

Are urinary tract infections contagious?

No. Urinary tract infections (UTIs) are not contagious.

What are urinary tract infection symptoms and signs?

Lower urinary tract infection

• Bladder (cystitis): The lining of the urethra and bladder becomes inflamed and irritated.
• Dysuria: pain or burning during urination
• Frequency: more frequent urination (or waking up at night to urinate, sometimes referred to as nocturia); often with only a small amount of urine
• Urinary urgency: the sensation of having to urinate urgently
• Cloudy, bad-smelling, or bloody urine
• Lower abdominal pain or pelvic pressure
• Mild fever (less than 101 F), chills, and "just not feeling well" (malaise)
• Urethra (urethritis): Burning with urination

Upper urinary tract infection (pyelonephritis)

Symptoms develop rapidly and may or may not include the symptoms for a lower urinary tract infection.

• Fairly high fever (higher than 101 F)
• Shaking chills
• Nausea
• Vomiting
• Flank pain: pain in the back or side, usually on only one side at about waist level

In newborns, infants, children, and elderly people, the classic symptoms of a urinary tract infection may not be present. Other symptoms may indicate a urinary tract infection.

• Newborns: fever or hypothermia (low temperature), poor feeding, jaundice
• Infants: vomiting, diarrhea, fever, poor feeding, not thriving
• Children: irritability, eating poorly, unexplained fever that doesn't go away, loss of bowel control, loose bowels, change in urination pattern
• Elderly people: fever or hypothermia, poor appetite, lethargy, change in mental cause

Pregnant women are at increased risk for an UTI. Typically, pregnant women do not have unusual or unique symptoms. If a woman is pregnant, her urine should be checked during prenatal visits because an unrecognized infection can cause pregnancy complications.
Although most people have symptoms with a urinary tract infection, some do not.
The symptoms of urinary tract infection can resemble those of sexually transmitted diseases.

When should people seek medical care for a UTI?

Any adult or child who develops any of the symptoms of a urinary tract infection needs to be evaluated by a medical professional, preferably within 24 hours. Most medical offices can test urine for infection by using a quick urine "dipstick" test.

• Someone who has symptoms of a lower urinary tract infection should call a health-care professional for an appointment, preferably on the same day that symptoms are recognized.
• Someone who has symptoms of an upper urinary tract infection involving the kidneys should call a health-care professional immediately. Depending on the situation, he or she will recommend either a visit to the office or to a hospital emergency department.

If someone has symptoms of a lower urinary tract infection and any of the following applies, he or she may have a urinary tract infection that can potentially be serious. Go to a hospital emergency department right away.

• Vomiting and inability to keep down clear fluids or medication
• Not better after taking antibiotics for two days
• Pregnant
• Having diabetes or another disease that affects the immune system
• Taking medication that suppresses the immune system such as cancer chemotherapy

Infants, children, and elderly people with any of the signs and symptoms of UTI should see their health-care professional as soon as possible or go to an emergency department for evaluation.

• Fever, lethargy, and poor appetite may indicate a urinary tract infection in these groups, but they may also be signs of something more serious.
• Urinary tract infections have the potential to make these vulnerable people very ill when the bacteria spread into the bloodstream.

How do physicians diagnose a urinary tract infection?

Diagnosis of a urinary tract infection is based on information someone gives about his or her symptoms, medical and surgical history, medications, habits, and lifestyle. A physical examination and lab tests complete the evaluation.
A doctor may simply perform a urine dipstick test in the office. Only a few minutes are needed to obtain results. A doctor may also send a urine sample to the lab for culture testing (see below). These results take a few days to come back. This tells the doctor the exact bacteria causing the infection and to which antibiotics these bacteria have resistance or sensitivity. The culture is usually sent for special populations, including men, because they are less likely to get UTIs. It is not necessary to send a culture for everyone because the majority of UTIs are caused by the same bacteria.

• The single most important lab test is urinalysis. A urine sample will be tested for signs of infection, such as the presence of white blood cells and bacteria.
• In certain circumstances, urine also may be "cultured." This means that a small amount of the urine is brushed on a sterile nutrient substance in a plastic plate. The plate is allowed to sit for a few days and then examined to see what kind of bacteria are growing on it. These bacteria are treated with different antibiotics to see which works best against them. This helps determine the best treatment for the specific infection.
• Blood tests usually are not required unless a complicated condition, such as pyelonephritis or kidney failure, is suspected.

For a culture specimen, the patient will be asked to give a clean-catch, midstream urine specimen. This avoids contamination of the urine with bacteria from the skin. Patients will be instructed in how to do this.

• Midstream means urinating a little into the toilet before collecting a specimen. The idea is to avoid collecting the urine that comes out first, as this urine is often contaminated.
• Clean-catch refers to a midstream sample that was collected after cleaning the area of the urethral opening.
• Adult women and older girls: Cleanse the area around the urethral opening gently (but completely) using a sterile wipe or soap and water. Catch the urine midstream. For some women, catheterization (inserting a tube into the bladder) may be the only way to obtain a sterile, uncontaminated specimen.
• Men and boys: A sterile specimen can usually be obtained with a midstream catch. Uncircumcised males should retract the foreskin and cleanse the area before urinating.
• Newborns: Urine may be obtained with a catheter or a procedure in which a needle is introduced through the lower abdominal wall to draw (aspirate) urine from the bladder.
• Infants and children: Either catheterization or the needle aspiration method is used.

If someone cannot produce a urine specimen or is unable to follow instructions for a clean-catch specimen, a health-care professional may obtain a urine specimen by catheterization.

• This means placing a thin tube (catheter) in the urethra to drain urine from the bladder.
• The catheter usually is removed after the bladder is emptied.
• The catheter may remain in place if someone is very ill or if it is necessary to collect all urine or measure urine output.
• An ultrasound examination can evaluate kidney and bladder problems.
• A fluoroscopic study can show any physical problems that predispose children to urinary tract infections.
• Intravenous pyelogram (IVP) is a special series of X-rays that uses a contrast dye to highlight abnormalities in the urinary tract.
• Cystoscopy involves insertion of a thin, flexible tube with a tiny camera on the end through the urethra into the bladder. This allows detection of abnormalities inside the bladder that might contribute to infections.
• A CT scan gives a very detailed three-dimensional picture of the urinary tract.

Imaging tests are most often needed for the following groups:

• Children with urinary tract infections, especially boys
• Up to 50% of infants and 30% of older children with a urinary tract infection have an anatomic abnormality. The child's pediatrician should investigate this possibility.
• Adults with frequent or recurrent urinary tract infections
• People who have blood in the urine

Are there home remedies for a urinary tract infection?

There are a variety of self-care measures (home remedies) and other treatments available for urinary tract infections.
Because the symptoms of a urinary tract infection mimic those of other conditions, someone should see a health-care professional if a urinary tract infection is suspected. A urine test is needed to confirm an infection. Self-care is not recommended.

It's possible to reduce the discomfort by taking the following steps:

• Follow the health-care professional's treatment recommendations.
• Finish all antibiotic medication even if feeling better before the medication is gone.
• Take a pain-relieving medication.
• Use a hot-water bottle to ease pain.
• Drink plenty of water.
• Avoid coffee, alcohol, and spicy foods, all of which irritate the bladder.
• Quit smoking. Smoking irritates the bladder and is known to cause bladder cancer.

What is the treatment for a urinary tract infection?

The usual treatment for both simple and complicated urinary tract infections is antibiotics. The type of antibiotic and duration of treatment depend on the circumstances.

Lower urinary tract infection (cystitis)

• In an otherwise healthy person, a three-day course of antibiotics is usually enough. Some providers prefer a seven-day course of antibiotics. Occasionally, a single dose of an antibiotic is used. A health-care professional will determine which of these options is best.
• In adult males, if the prostate is also infected (prostatitis), four weeks or more of antibiotic treatment may be required.
• Adult females with potential for or early involvement of the kidneys, urinary tract abnormalities, or diabetes are usually given a five- to seven-day course of antibiotics.
• Children with uncomplicated cystitis are usually given a 10-day course of antibiotics.
• To alleviate burning pain during urination, phenazopyridine (Pyridium) or a similar drug, can be used in addition to antibiotics for one to two days.

  Upper urinary tract infection (pyelonephritis)

• Young, otherwise healthy patients with symptoms of pyelonephritis can be treated as outpatients. They may receive IV fluids and antibiotics or an injection of antibiotics in the emergency department, followed by 10-14 days of oral antibiotics. They should follow up with their health-care professional in one to two days to monitor improvement.
• If someone is very ill, dehydrated, or unable to keep anything in his or her stomach because of vomiting, an IV will be inserted into the arm. He or she will be admitted to the hospital and given fluids and antibiotics through the IV until he/she is well enough to switch to an oral antibiotic.
• A complicated infection may require treatment for several weeks.

• Appear very ill
• Are pregnant
• Have not gotten better with outpatient antibiotic treatment
• Have underlying diseases that compromise the immune system (diabetes is one example) or are taking immunosuppressive medication
• Are unable to keep anything in the stomach because of nausea or vomiting
• Had previous kidney disease, especially pyelonephritis, within the last 30 days
• Have a device such as a urinary catheter in place
• Have kidney stones

Urethritis in men and women can be caused by the same bacteria as sexually transmitted diseases (STDs). Therefore, people with symptoms of STDs (vaginal or penile discharge for example) should be treated with appropriate antibiotics.

What follow-up is needed for a urinary tract infection?

Follow a health-care professional's treatment recommendations. Finish all medications even if feeling better before the medication is gone. A health-care professional will want the patient to have a follow-up appointment to repeat the urinalysis and make sure he or she is getting better.

• Children and adults with kidney involvement should be seen again in one to two days.
• People recovering from uncomplicated lower urinary tract infections should be seen within one week.

Occasionally, the infection does not go away with the first treatment. If someone is being treated for an infection and has any of the following, call a health-care professional promptly:

• Fever or pain with urination is not gone after two days of antibiotic treatment.
• Someone cannot keep the medication down or it has severe side effects.
• Someone is unable to keep foods, fluids, or medication down because of nausea or vomiting.
• Someone develops signs of kidney involvement (such as flank pain, shaking chills, high fever).
• Someone's symptoms are worse rather than better after two days of antibiotics.