Urinary Tract Infections in Teens and Adults

Topic Overview

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This topic is about urinary tract infections in teens and adults. For information about infections in babies and young children, see the topic Urinary Tract Infections in Children.

What is a urinary tract infection?

Your urinary tract is the system that makes urine and carries it out of your body. It includes your bladder and kidneys and the tubes that connect them. When germs get into this system, they can cause an infection.

Most urinary tract infections are bladder infections. A bladder infection usually is not serious if it is treated right away. If you do not take care of a bladder infection, it can spread to your kidneys. A kidney infection is serious and can cause permanent damage.

What causes urinary tract infections?

Usually, germs get into your system through your urethra-the tube that carries urine from your bladder to the outside of your body. The germs that usually cause these infections live in your large intestine and are found in your stool. If these germs get inside your urethra, they can travel up into your bladder and kidneys and cause an infection.

Women tend to get more bladder infections than men. This is probably because women have shorter urethras, so it is easier for the germs to move up to their bladders. Having sex can make it easier for germs to get into your urethra.

You may be more likely to get an infection if you do not drink enough fluids, you have diabetes, or you are pregnant. The chance that you will get a bladder infection is higher if you have any problem that blocks the flow of urine from your bladder. Examples include having kidney stones or an enlarged prostate gland.

For reasons that are not well understood, some women get bladder infections again and again.

What are the symptoms?

You may have an infection if you have any of these symptoms:

• You feel pain or burning when you urinate.
• You feel like you have to urinate often, but not much urine comes out when you do.
• Your belly feels tender or heavy.
• Your urine is cloudy or smells bad.
• You have pain on one side of your back under your ribs. This is where your kidneys are.
• You have fever and chills.
• You have nausea and vomiting.

Call your doctor right away if you think you have an infection and:

• You have a fever, nausea and vomiting, or pain in one side of your back under your ribs.
• You have diabetes, kidney problems, or a weak immune system.
• You are older than 65.
• You are pregnant.

How are urinary tract infections diagnosed?

Your doctor will ask for a sample of your urine. It is tested to see if it has germs that cause bladder infections.

If you have infections often, you may need extra testing to find out why.

How are they treated?

Antibiotics prescribed by your doctor will usually cure a bladder infection. It may help to drink lots of water and other fluids and to urinate often, emptying your bladder each time.

If your doctor prescribes antibiotics, take the pills exactly as you are told. Do not stop taking them just because you feel better. You need to finish taking them all so that you do not get sick again.

Can urinary tract infections be prevented?

You can help prevent these infections.

• Drink lots of water every day.
• Try drinking cranberry juice or taking cranberry pills.
• Urinate often. Do not try to hold it.
• If you are a woman, urinate right after having sex.

Frequently Asked Questions

Cause

Bacteria that enter the urethra and travel up the urinary tract are the usual cause of urinary tract infections (UTIs). Bacteria that normally live in the large intestine and are present in feces (stool) are the most common source of infection. Sexual intercourse may introduce bacteria into the urinary tract, especially in women. Catheters, which are small, flexible tubes inserted into the bladder to allow urine to drain, are a common source of bacterial infection in people who are hospitalized or live in long-term care facilities.

Occasionally, bacteria traveling through the blood or lymph system cause kidney or bladder infections.

Kidney stones, an enlarged prostate in men, and structural problems in the urinary tract can contribute to UTIs by limiting the body's ability to eliminate urine completely.

Symptoms

Symptoms of a urinary tract infection (UTI) may include:

• Pain or burning when you urinate.
• An urge to urinate frequently but usually passing only small amounts of urine.
• Dribbling (inability to control urine release).
• Pain or a feeling of heaviness in your lower abdomen.
• Reddish or pinkish urine.
• Foul-smelling urine.
• Cloudy urine.
• Pain in your back just below the rib cage, on one side of your body (flank pain).
• Fever and chills.
• Nausea and vomiting.

Some people have bacteria in their urinary tract without having any symptoms. This condition is called asymptomatic bacteriuria. It requires attention in certain situations, such as during pregnancy or before surgery involving the urinary tract, but it usually can be left alone if symptoms do not develop.

Several other conditions, such as vaginal infections or irritable bladder, cause symptoms similar to those of a UTI. Your doctor may evaluate your health for one or more of these if you have urinary symptoms, depending on your medical history and how well you respond to treatment for a UTI.

What Happens

Urinary tract infections (UTIs) typically occur when bacteria from the rectal area enter through the urethra, which is a tube that carries urine, and travel up the urinary tract to the bladder or kidneys.

When a bacterial UTI is present but does not cause symptoms, it is called asymptomatic bacteriuria. These types of infections often affect pregnant women, as well as older adults or those who require a catheter to urinate. Pregnant women are screened for asymptomatic bacteriuria, because it can cause preterm labor and other problems if not treated. Asymptomatic bacteriuria may lead to infections that cause symptoms, but in many cases it does not. It usually goes away without treatment.

Typically, UTIs cause urinary symptoms, such as pain or burning during urination. Some mild bladder infections may go away on their own within a couple of days. Most UTIs clear up quickly with antibiotics and home treatment, which includes drinking plenty of water and urinating frequently. The amount of time required to cure the infection and the need for urine tests will vary with the location (bladder or kidneys), frequency, and seriousness of the infection. Kidney infections and UTIs that are complicated by other factors require longer treatment.

Complications of UTIs are not common but do occur. Serious complications can include permanent kidney damage and widespread infection (sepsis), which can be life-threatening. The risk is greater if the infection is not treated or if the infection does not respond to antibiotics.

Although it is possible to have a relapse of the same infection, most recurrent UTIs are caused by new infections. About 20% to 30% of women have recurrent infections.¹ A rapid relapse usually means that treatment failed or there is another problem affecting the urinary tract (not just the infection). But recurrent UTIs in women usually aren't serious.

UTIs in men

Men sometimes develop uncomplicated urinary tract infections.

UTIs in older men are more often related to prostate problems. This can make them more difficult to treat. Having an enlarged prostate, which is common in older men, can limit the body's ability to pass urine. Repeated UTIs may indicate prostatitis, epididymitis, or another urinary tract problem. For more information, see the topic Prostatitis.

What Increases Your Risk

Risk factors in women

Urinary tract infections (UTIs) are most common in young to middle-aged sexually active women. Things that increase a woman's risk of getting UTIs include:

• Sexual activity, which pushes bacteria into the urethra. Sexual activity with the use of a diaphragm and spermicide raises the risk.
• Pregnancy. Pregnant women are at risk of developing asymptomatic bacteriuria, which in turn increases the risk of infections that cause symptoms. It also increases the risk of preterm labor.
• Previous UTIs.
• Use of feminine hygiene products that contain deodorant.
• Lack of estrogen, which allows bacteria that can cause UTIs to grow more easily in the vagina or urethra. Women who have gone through menopause are at increased risk for UTIs.

Risk factors in men

Things that increase a man's risk of UTIs include:

• Problems with the prostate gland. Men become increasingly prone to UTIs as they get older because of prostate problems, such as enlarged prostate (benign prostatic hyperplasia) and prostatitis.
• An uncircumcised penis.
• Anal intercourse.
• Unprotected sex with a woman who has a vaginal infection.
• HIV infection.

Risk factors in both women and men

Certain risk factors apply to both women and men. These include:

• Not drinking enough fluids. Drinking more fluids causes increased urination, reducing bacteria in the urinary tract and bladder.
• Having a catheter in place. A catheter is a small, flexible tube inserted through the urethra and into the bladder, allowing urine to drain. Bacteria can enter the catheter and start an infection. Most at risk are older adults who are in hospitals or who live in long-term care facilities. Catheterization also greatly increases the risk for asymptomatic bacteriuria.
• Kidney stones and other obstructions in the urinary tract. These may block the flow of urine, increasing the risk of bacterial infection.
• Diabetes. People with diabetes are at greater risk for UTIs because their immune systems are weakened. Also, long-term high blood sugar can damage the kidneys' filtering system (diabetic nephropathy).
• Structural problems of the urinary tract. These may be present at birth or develop later in life.

When To Call a Doctor

Call your doctor immediately if painful urination or other symptoms of a urinary tract infection (UTI) occur with:

• Nausea and vomiting.
• Fever and chills.
• Pain in the back just below the rib cage, on one side of your body (flank pain).
• Pregnancy.

Call a doctor if you:

• Have had UTI symptoms previously and have those symptoms again.
• Have minor symptoms of a UTI that do not clear up in 1 to 2 days, such as pain or burning when you urinate, foul-smelling urine, or the urge to urinate frequently while passing only small amounts of urine.
• Notice blood or pus in your urine.
• Have symptoms of a UTI and you have diabetes.
• Have been taking antibiotics for a UTI but your symptoms do not improve or they come back (recur) after improving temporarily.

Watchful Waiting

Watchful waiting is a wait-and-see approach. If you get better on your own, you won't need treatment. If you get worse, you and your doctor will decide what to do next.

In adults, home treatment for minor urinary tract infections (UTIs) often resolves the problem. Home treatment includes drinking plenty of water and urinating often, emptying the bladder each time.

• Try home treatment for 1 to 2 days if your symptoms are minor.
• If your symptoms last longer than 1 to 2 days or are severe, seek medical help.

Watchful waiting is not appropriate if you:

• Have diabetes or an impaired immune system.
• Are pregnant.
• Are older than 65.

Who To See

The following health professionals can treat urinary tract infections (UTIs):

• Nurse practitioner
• Physician assistant
• General practitioner
• Family medicine physician
• Internist
• Obstetrician
• Gynecologist
• Urologist

To prepare for your appointment, see the topic Making the Most of Your Appointment.

Exams and Tests

If you have symptoms of a urinary tract infection (UTI), your initial evaluation by a doctor will probably include:

• A medical history and physical exam.
• Urinalysis.

Your doctor may order a urine culture to confirm the diagnosis of a suspected UTI. But if your symptoms, medical history, and urinalysis make the presence of an uncomplicated urinary tract infection likely, your doctor may have you begin treatment with antibiotics without waiting for the results of a urine culture.

A doctor may order a urine culture:

• For women with unusual UTI symptoms, such as symptoms that last longer than 7 days, or symptoms of a kidney infection (pyelonephritis).
• For men before and after treatment for a UTI.
• For anyone older than 65 with UTI symptoms.
• If you have diabetes, an impaired immune system, or structural problems in your urinary tract.
• If your UTI symptoms return after 3 days of treatment. A urine culture can identify what type of bacteria is causing the infection, so that the most effective antibiotic for that bacteria can be used.
• After treatment for a UTI in people who have kidney infections (pyelonephritis), to make sure the infection is cured.
• To screen young girls for asymptomatic bacteriuria.

If you are pregnant, your doctor may order a urine culture:

• If you have UTI symptoms.
• After treatment for a UTI.
• To screen for asymptomatic bacteriuria.

Tests used less frequently

If the infection does not respond to treatment with antibiotics or recurs rapidly, if the infection may be complicated by other factors, or, in some cases, if the kidneys are infected, your doctor may order other tests to:

• Determine the cause of recurrent or chronic infections.
• Check for other kidney problems.
• Diagnose structural problems of the urinary tract that might make you more likely to get UTIs.
• Determine whether the infection is caused by unusual bacteria.
• Determine whether you have an impaired immune system.

Tests used for these purposes may include:

• Abdominal ultrasound, which uses reflected sound waves to produce a picture of the upper abdomen.
• Pelvic ultrasound, which uses reflected sound waves to produce a picture of the lower abdomen.
• Voiding cystourethrogram, which is an X-ray test that takes pictures of your bladder and urethra while you are urinating.
• Cystometry, which measures your bladder's ability to hold in and push out water or gas.
• Cystoscopy, which allows your doctor to look at the interior lining of the bladder and the urethra.
• Intravenous pyelogram (IVP), an X-ray test that provides pictures of the size, shape, and position of the kidneys, bladder, ureters, and urethra.
• Spiral (helical) CT urogram, a high-speed (about 90 seconds) scanner that provides detailed pictures of the area scanned.

Early Detection

Experts disagree about the value and cost-effectiveness of screening people who are at high risk for urinary tract infections. Factors that increase the risk for UTIs include previous UTIs, using condoms coated with spermicide, and prostate problems.

All pregnant women should receive screening for asymptomatic bacteriuria.

Treatment Overview

Antibiotics can treat most urinary tract infections (UTIs) successfully. The goals of treatment for UTIs are to relieve symptoms, eliminate the infection and prevent recurrence, and prevent unlikely but serious complications such as kidney damage and sepsis. In pregnant women, treatment protects the woman and the fetus.

Initial treatment

Treatment for uncomplicated bladder infections in women usually is 3 days of antibiotics. Home treatment includes drinking a lot of water and fluids and urinating frequently, emptying your bladder each time. Additional testing is not necessary if your symptoms improve.

Oral antibiotics usually can treat kidney infections (pyelonephritis), although you may need brief hospitalization and a short course of intravenous (IV) antibiotics if you are too ill or nauseated to take medicine by mouth (oral medication). Kidney infections tend to make people more severely ill than bladder infections. After you are feeling better, you may take oral antibiotics, typically for about 2 weeks. Your doctor probably will test your urine for bacteria after treatment, to be certain you no longer have an infection.

Your antibiotic treatment may take longer and you may require further testing before and after treatment if you:

• Are pregnant.
• Are older than 65.
• Have diabetes or an impaired immune system.
• Are a man. UTIs in men typically require 1 to 2 weeks of antibiotics. Additional testing and treatment for prostate problems (such as prostatitis) or sexually transmitted diseases (such as chlamydia or gonorrhea) may be necessary.

If you have a severe kidney infection, or if a bladder or kidney infection is complicated by other factors, you may need hospitalization.

Treatment if the condition gets worse or recurs

If your urinary tract infection (UTI) does not improve after treatment with antibiotics, you will need further evaluation and additional antibiotic treatment.

If the infection spreads and affects your kidney function or causes widespread infection (sepsis), you will need hospital care. These complications are not common, and they rarely occur in people who are otherwise healthy. People are at higher risk if they have an impaired immune system, diabetes, untreated urinary tract obstruction, and/or other conditions that affect the kidneys or bladder.

A new infection, rather than a relapse of the same infection, usually is the cause of a UTI that keeps coming back (recurs).

• Women with recurrent bladder infections may take antibiotics for 6 months, followed by preventive antibiotic therapy.¹
• Recurrent UTIs in men are usually a sign of prostate infection (prostatitis). Chronic prostatitis can be difficult to treat and may take up to 6 weeks of antibiotic therapy. For more information, see the topic Prostatitis. Follow-up checkups are usually necessary in men who have UTIs and are always necessary if the infection recurs.

What To Think About

Your doctor may base treatment decisions for a bladder infection on your symptoms and urinalysis results, without doing a urine culture. If treatment clears up the symptoms, it confirms the diagnosis of a simple, uncomplicated UTI. If the symptoms do not clear up, you will need further testing to look for:

• A kidney infection.
• Structural problems with the kidneys that increase the risk of infection.
• Infection with an uncommon bacteria.
• An impaired immune system.
• A cause for the symptoms that is not an infection.

If group B streptococcal infection causes a UTI in a pregnant woman, she will receive antibiotic treatment during labor so that she does not pass the infection to her baby.²

Many forms of bacteria have become resistant to common antibiotics designed to destroy them. These are called antibiotic-resistant bacteria. Antibiotic resistance among bacteria that cause UTIs has increased steadily in recent decades.

You and your doctor may have to try different antibiotics, and different combinations of antibiotics, to find the right medication that will kill the bacteria causing the UTI. But in most cases, a urine culture and antibiotic sensitivity test will help find the right antibiotic to use.

Prevention

You can take steps to prevent new or relapsing urinary tract infections (UTIs).

Prevention steps for men and women

• Drink plenty of water and other liquids each day. This helps ensure that you urinate frequently, which flushes bacteria from your urinary tract.
• Urinate when you have the urge. Don't hold your urine for a long time.
• Avoid constipation.
• Drink cranberry juice or take cranberry pills.³

Prevention steps for women

• Urinate immediately after sexual intercourse. This is the best protection women have against UTIs, because it helps prevent bacteria from moving into the urethra.
• Avoid using a condoms coated with spermicide or a diaphragm for birth control if your doctor believes they are causing you to get UTIs.
• Change sanitary napkins often.
• Avoid douches, feminine hygiene sprays, and other feminine hygiene products with deodorant. These can alter the normal balance of organisms that help prevent infection.

Prevention step for men

• Keep the tip of your penis clean, especially if you are uncircumcised. The foreskin can trap bacteria, which can then get into the urinary tract and cause infection.

Home Treatment

You may be able to cure an early urinary tract infection (UTI) if you act promptly when you have the first symptoms of a UTI, such as pain and burning with urination. Home treatment steps that may stop an infection from progressing include:

• Drinking lots of water, especially during the first 24 hours after your symptoms appear. This will help make the urine less concentrated and wash out the infection-causing bacteria. This may alter some of your body's normal defense mechanisms, but most doctors recommend drinking a lot of fluids when you have a UTI. Some people also drink cranberry juice.
• Urinating frequently and completely, to empty your bladder each time.

To relieve pain, take a hot bath or lay a heating pad over your genital area. Never go to sleep with a heating pad in place.

Self-treatment of recurrent UTIs

If you are a woman who has frequent uncomplicated UTIs, your doctor may write a standing prescription for antibiotics to take if you develop symptoms of a UTI. If you and your doctor agree to follow this approach and you develop symptoms that you are certain are caused by a UTI, follow your doctor's instructions for taking the medicine and for monitoring your symptoms. Be sure to notify your doctor if your symptoms do not improve or if you start having UTIs more often than in the past.

Medications

Oral antibiotics can treat most bladder infections and uncomplicated kidney infections successfully. In many cases, if the symptoms and urinalysis suggest a urinary tract infection (UTI), you will start taking antibiotics without waiting for the results of a urine culture.

How long you will need to take antibiotics depends on the location of the infection, your age, your gender, and any complicating medical conditions.

• Women with uncomplicated bladder infections (cystitis) usually take antibiotics for 3 days. In the past, longer courses of treatment were common, but studies show that the shorter course of antibiotics is just as effective and causes fewer side effects.⁴
• Women with bladder infections who have had a recent UTI or who have symptoms for more than 7 days may require a 7-day course of antibiotics.
• Men with bladder infections usually take antibiotics for 7 to 14 days. If the prostate is infected as well, treatment may last 4 weeks or more.
• Men and women with kidney infections (pyelonephritis) may take antibiotics for 10 to 14 days. In severe cases, treatment may require intravenous (IV) antibiotics and fluids in a hospital.
• Men and women who are older than 65, have diabetes or an impaired immune system, or have other urinary problems usually require longer courses of antibiotics.
• People who have infections that do not respond to treatment or are complicated by other factors may require longer antibiotic therapy.

Antibiotics for recurrent infections

Doctors sometimes advise that women with repeat infections take antibiotics for 2 to 6 weeks, followed by preventive antibiotic therapy. This may include taking a small dose of antibiotics daily or on alternate days, taking antibiotics after sexual intercourse (since sex often triggers UTIs in women with recurrent infections), or taking antibiotics only when you develop symptoms. Talk with your doctor about which treatment strategy is appropriate for you.

Medication Choices

Antibiotic medications that treat UTIs include:

• Sulfonamides with trimethoprim (such as Bactrim or Septra).
• Trimethoprim (Proloprim).
• Fluoroquinolones (such as Cipro or Floxin).
• Cephalosporins (such as Keflex or Duricef).
• Nitrofurantoin (such as Macrobid or Macrodantin).
• Penicillins (such as ampicillin or amoxicillin).
• Tetracycline (such as Declomycin or Vibramycin).

Phenazopyridine treats the pain and burning that often accompany a UTI.

Be sure to tell your doctor if you are or think you may be pregnant. Some of these medications are not safe to use during pregnancy.

What To Think About

These medicines are often prescribed in a less costly generic form, rather than under a brand name. A pharmacist might also decide to give you a generic instead of a brand name medicine unless the prescription says "no generic."

Take all of the antibiotics your doctor has prescribed. Most people begin to feel better soon after they begin the medicine. But if you stop taking the medicine as soon as you feel better, the infection may return. More importantly, not taking the full course of antibiotics encourages the development of bacteria that are resistant to antibiotics. This not only makes antibiotics less effective but also makes bacterial infections more difficult to treat.

Many forms of bacteria have become resistant to common antibiotics designed to destroy them. These are called antibiotic-resistant bacteria. Antibiotic resistance among bacteria that cause UTIs has increased steadily in recent decades. You and your doctor may have to try different antibiotics, and different combinations of antibiotics, to find the right medication that will kill the bacteria causing your UTI. Before starting you on a new antibiotic, your doctor may get a urine sample from you. Results from tests on this sample will help guide the decision on which antibiotic you take next.

If your doctor prescribes antibiotics, ask whether there are any potential drug interactions you should be aware of. For instance, some antibiotics used to treat UTIs may make birth control pills less effective. Your doctor may recommend a backup form of birth control. Antibiotics can also reduce the effectiveness of warfarin (Coumadin), an anticoagulant (blood thinner) that lowers the risk of heart attack and stroke in people at high risk for these conditions.

Antibiotics for recurrent UTIs

For women who have recurrent UTIs, some doctors may write a standing prescription for antibiotics that a woman can take as soon as she has symptoms of a UTI. This saves the cost and inconvenience of a clinic visit. It also allows a woman familiar with the typical symptoms of a UTI to begin treating the infection without delay.⁵ Talk with your doctor about whether this self-treatment strategy is right for you. If you and your doctor have agreed to follow this approach and you develop symptoms that you are certain are caused by a UTI, follow your doctor's instructions for taking the medicine and for monitoring your symptoms.

Be sure to notify your doctor if your symptoms do not improve or if you start having UTIs more often than in the past.

Surgery

There is no surgical treatment for urinary tract infections (UTIs) at this time. If you have a problem with the structure of your urinary tract that is causing frequent UTIs, you and your doctor may want to consider surgery to correct the problem.

Other Treatment

Drinking cranberry juice or taking a cranberry supplement may help prevent urinary tract infections (UTIs). More study is needed to prove this. Cranberry is not well tested as a cure for UTI.³

Other Places To Get Help

Organizations

Related Information

• Urinary Problems and Injuries, Age 12 and Older
• Urinary Tract Infections in Children

References

Citations

1. Gupta K, Stamm WE (2005). Urinary tract infections. In DC Dale, DD Federman, eds., ACP Medicine, section 7, chap. 23. New York: WebMD.

2. Schrag S, et al. (2002). Prevention of perinatal group B streptococcal disease: Revised guidelines from CDC. MMWR, 51(RR-11): 1-22.

3. National Center for Complementary and Alternative Medicine (2005). Cranberry. Herbs at a Glance. Available online: http://nccam.nih.gov/health/cranberry.

4. Miller LG, Tang AW (2004). Treatment of uncomplicated urinary tract infections in an era of increasing antimicrobial resistance. Mayo Clinical Procedures, 79(8): 1048-1054.

5. Sen A (2006). Recurrent cystitis in non-pregnant women. Clinical Evidence (15): 2558-2564.

Other Works Consulted

• Albert X, et al. (2006). Antibiotics for preventing recurrent urinary tract infection in non-pregnant women. Cochrane Database of Systematic Reviews (1). Oxford: Update Software.

• Talan DA, et al. (2004). Once daily, extended release ciprofloxacin for complicated urinary tract infections and acute uncomplicated pyelonephritis. Journal of Urology, 171(2, Part 1): 734-739.

• Vogel T, et al. (2004). Optimal duration of antibiotic therapy for uncomplicated urinary tract infection in older women: A double-blind randomized controlled trial. Canadian Medical Association Journal, 170(4): 469-473.

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