Urinary Tract Infections : Overview

Urinary Tract Infection is an abbreviation for urinary tract infection. A urinary tract infection is a bacterial infection that occurs anywhere along the urinary tract. (Urine is normally sterile, containing only salts, fluids and waste products.) Women have a higher risk of developing UTIs than men. As many as one in five women will experience a UTI at some point in their lives, according to the National Kidney Foundation.

UTIs account for almost 10 million office visits and 1.6 million hospitalizations each year. A bacterium called Staphylococcus saprophyticus is the most common cause of UTIs in younger women. Another bacterium called Escherichia coli (E. coli) also frequently causes infections in the urinary tract. In addition, urinary tract infections may be caused by bacteria transmitted during sexual intercourse.

The urinary tract and UTI progression

The urinary tract includes the following organs:

• Kidneys. A pair of organs located in the back of the abdomen and next to the spine. They remove wastes and extra water from the blood to make urine.
• Bladder. A hollow, balloon-shaped organ in the lower abdomen. It stores urine and releases it when full.
• Ureters. The two long, hollow tubes that transfer urine from the kidneys to the bladder.
• Urethra. The tube that carries urine from the bladder to the outside of the body during urination.

Infection occurs when bacteria adhere to the opening of the urethra and start to multiply. A UTI that affects the urethra is called urethritis. If this condition is not treated immediately, bacteria can travel to the bladder. This may cause a bladder infection, which is also called cystitis. If cystitis is not treated promptly, the bacteria can spread to the kidneys. The resulting kidney infection, called pyelonephritis, is the most serious type of UTI. When a UTI becomes this serious, it can spread to the bloodstream.

Although all of the organs in the urinary tract can become infected, most urinary tract infections impact only the lower tract, which consists of the urethra and bladder. The presence of bacteria in the urine does not always indicate an infection. Some people, especially older people, have bacteria in the bladder that do not cause any symptoms. This condition, known as asymptomatic bacteriuria, does not typically pose any health risks. However, if pregnant women develop this condition, they are at a greater risk for pyelonephritis. Therefore, pregnant women with asymptomatic bacteriuria are generally treated with antibiotics to prevent kidney infection and potential complications.

UTIs can be painful and irritating. If these infections spread to the kidneys and bloodstream, they can cause serious health problems, such as sepsis. Sepsis is a life-threatening blood infection. Other serious complications of UTIs include widespread infections, abscesses (collections of pus) and inflammation of the bladder wall. These complications mainly affect people with diabetes.

Diagnosis of a UTI includes a thorough medical examination and tests, such as a urinalysis and urine culture, to identify the cause of the infection, which is generally treated with antibiotics. UTIs can often be prevented by urinating frequently, drinking plenty of water and wiping from front to back after using the toilet.

Risk factors for UTIs

In most people, infection does not occur when bacteria enter the urinary tract. Normally, the body removes the bacteria through urination. However, in certain people the likelihood of developing a UTI is increased. These include:

• Women. Women are more likely to develop UTIs than men because their urethras are shorter. This means that bacteria have less distance to travel.
• People with conditions that affect the immune system. If you have diabetes or another condition that affects your immune system, you have a greater risk of a UTI. People with diabetes have decreased immune system function and excess blood sugar, both of which promote the growth and spread of bacteria.
• Older people. Infections of the urinary tract commonly affect the elderly, especially those who can't control their bladder or require frequent catheterization. Catheterization involves inserting a sterile, hollow tube into the bladder, often through the urethra to remove urine from the body. Both of these factors encourage easy entry of bacteria into the urinary system.
• Women going through menopause. If you are experiencing menopause, you have an increased risk of developing a UTI. This is because the walls of your vagina and urethra are thinner than previously. This reduces your body's resistance to bacteria. Hormone replacement therapy can often help patients prevent UTIs and other menopause-related side effects.
• People who are sexually active. Sexual activity is also commonly associated with urinary tract infections. This is because sexual intercourse can introduce bacteria into the urethra. In addition, the use of some types of contraceptives, such as spermicides and diaphragms, may increase your risk of UTIs. While sexual activity is most often a risk factor for women, a small number of men may also contract an infection of the urinary tract through intercourse with an infected partner. This risk is greater in men who are uncircumcised.
• People with a sexually transmitted disease (STD). Having certain STDs, such as chlamydia or herpes simplex virus, increases the odds of contracting a UTI. The bacteria responsible for the STDs can produce microorganisms which spread to the urethra and bladder, resulting in a urinary tract infection.

Other conditions that may be mistaken for UTIs

Burning, frequent urination and urinary urgency are common symptoms of UTIs. However, they may also indicate the presence of another condition called urethral syndrome. Urethral syndrome is the name given to a group of symptoms that affect the bladder but cannot be attributed to a specific cause, such as bacterial infection. Only a physician can determine whether a UTI or urethral syndrome is present.

A condition known as interstitial cystitis can also cause symptoms that mimic a urinary tract infection. Interstitial cystitis is an inflammation of the bladder wall that is not related to an infection. If you continue to experience symptoms of an infection despite cultures indicating no infection, you should be evaluated by a urologist to see if you have this condition.

UTIs are common concerns for many women, but if they're treated promptly, they are likely to be nothing more than a temporary nuisance.