A urinary tract infection, also known as a bladder infection or acute cystitis, is an infection of a part or parts of the female or male urinary tract. The urinary tract is made up of the ureters, kidneys, urethra and bladder. A urinary tract infection (UTI) is not technically a sexually transmitted one; however, sexual activity is a common cause of UTI's for adults who are sexually active. When the infection affects the lower urinary tract the condition is known as a, 'simple cystitis,' or bladder infection. When it affects the upper urinary tract it is known as, 'pyelonephritis,' or a kidney infection. The most common cause of UTI's is the bacterium, Escherichia coli (E. coli), commonly found in the lower intestine.
A urinary tract infection (UTI) (also known as acute cystitis or bladder infection) is an infection that affects part of the urinary tract. The bladder is a small, balloon-shaped organ located in the pelvis. In women, the bladder is located in front of the uterus. In men, the bladder is located just above the prostate gland. When it affects the lower urinary tract it is known as a simple cystitis (a bladder infection) and when it affects the upper urinary tract it is known as pyelonephritis (a kidney infection). Symptoms from a lower urinary tract include painful urination and either frequent urination or urge to urinate (or both), while those of pyelonephritis include fever and flank pain in addition to the symptoms of a lower UTI. In the elderly and the very young, symptoms may be vague or non-specific. The main causal agent of both types is Escherichia coli, though other bacteria, viruses or fungi may rarely be the cause. Upper UTIs are infections of the kidneys. These are potentially life threatening, if bacteria move from the infected kidney into the blood. This condition is called sepsis. Sepsis can cause dangerously low blood pressures, shock, and death.
Females are at an increased risk of developing a UTI than males. The reason why is likely due to the fact that biological females have a shorter urethra than males, effectively reducing the distance that bacteria have to travel to reach a female's bladder. Approximately half of all females experience at least 1 infection at some point during their lives. Urinary tract infections may vary greatly in their difficulty to treat. Some instances require only a short course of antibiotics, while others need more invasive methods of treatment such as dialysis.
Signs or symptoms of a urinary tract infection may not always be noticeable, yet if symptoms are present they will usually manifest in one of the following ways. A person may experience a strong and persistent urge to urinate, a burning sensation while urinating, frequent, small amounts of urine, or urine that seems to be cloudy. Symptoms may also include:
UTI symptoms might also vary depending upon which part of the person's urinary tract is infected. If only the urethra is infected, burning with urination should be the only symptom the person notices. Infection of a person's urethra is known as, 'urethritis.' If the infection involves a person's bladder, the infection is called, 'cystitis,' and might cause the person to experience symptoms such as:
The majority of UTI's involve only a person's bladder and urethra. Serious infections; however, might spread to the upper urinary system, which includes a person's ureters and kidneys, resulting in an infection known as, 'acute pyelonephritis.' Acute pyelonephritis is a very serious medical condition in which the infection has opportunity to enter a person's bloodstream and spread to other healthy tissues in their body.
If a blood infection such as this happens, a person's risk of mortality increases significantly - especially in children and seniors. The presentation of acute pyelonephritis is distinct from that of the less severe lower tract infections and usually includes symptoms that may include:
Signs and symptoms of a urinary tract infection (UTI) may be particularly hard to observe in children and seniors. In young children, the only symptom of a UTI may be a fever. Infants might also feed poorly, sleep excessively, vomit, or show signs of jaundice. In older children, a loss of bladder control may happen. UTI symptoms in seniors can be even more vague, at times presenting as incontinence, general fatigue, or a change in mental status. Diagnosis of UTI's in seniors may be further complicated by pre-existing or comorbid incontinence or dementia.
Urinary tract infections usually occur when bacteria enter a person's urinary tract through the urethra and start to multiply in the person's bladder, at times spreading to other nearby tissues. While the human urinary system is designed to keep out microscopic invaders, these defenses are not perfect and at times fail. When this happens, bacteria might take the opportunity to secure a habitat and grow into an infection in the person's urinary tract.
Infection may also happen through a person's blood or lymph. The common intestinal bacterium E. coli causes 80-85% of urinary tract infections. After entering a person's bladder, E. coli are able to attach to the person's bladder wall and form a biofilm that resists the person's immune system. Other bacteria; however, such as Staphylococcus saprophyticus, or viruses and fungi, may also cause UTI's. Risk factors for contracting a UTI may include the following circumstances:
A predisposition for bladder infections might run in some families.
People who are sexually active tend to have more UTI's than people who are not sexually active.
Kidney stones, or an enlarged prostate, may trap urine in the bladder and increase the risk of contracting a UTI.
Diabetes and other diseases that impair a person's immune system may increase the risk of contracting a UTI.
After menopause, UTI's may become more common due to a lack of estrogen which causes changes in a female's urinary tract, making it more vulnerable to infection.
Research has shown that females who use diaphragms for birth control might be at an increased risk of contracting a UTI, as well as females who use spermicidal agents.
Infants born with urinary tract abnormalities that do not permit urine to exit their bodies as usual, or cause urine to back up in the urethra, experience an increased risk of contracting a UTI.
People who are unable to urinate on their own and use a catheter to urinate have an increased risk of UTI's. People at risk may include those who are hospitalized, those with neurological issues that make it hard to control their ability to urinate, as well as people who experience paralysis.
A doctor might use a number of different tests and procedures to diagnose a UTI. The tests could include the following:
A doctor may ask for a urine sample for laboratory analysis to look for white blood cells, bacteria, or red blood cells. To avoid potential contamination of the sample, you may be instructed to wipe your genital area with an antiseptic pad and collect the urine in midstream.
Lab analysis of a person's urine is at times followed by a urine culture, which is a test that uses the urine sample to grow bacteria in a laboratory. The test tells a doctor which bacteria are causing the person's infection and which medications will be best for treatment.
If a doctor suspects that an abnormality in your urinary tract causes frequent infections, you might be asked to complete an ultrasound or a CT scan to create images of your urinary tract. In some situations, a doctor might also use a contrast dye to highlight certain structures in your urinary tract. Another test called an, 'intravenous pyelogram (IVP),' uses X-rays with contrast dye to create images.
If you experience recurrent UTI's, a doctor may perform a cystoscopy using a long and thin tube with a lens to see inside of your urethra and bladder. The cystoscope is inserted into your urethra and passed through to your bladder.
Although UTI symptoms are already vague at times, a diagnostic physician must not only diagnose the infection - but also differentiate this vague condition from a large variety of other, similarly vague conditions. People with an inflamed vagina may actually be experiencing a yeast infection for example. Because yeast is a fungus instead of a bacterium, the methods of treating this kind of infection are different from those used for UTI's. Inflammation of a person's prostate might also be considered in the doctor's differential diagnosis.
When provided with appropriate and prompt treatment, lower urinary tract infections rarely lead to additional health issues. If left untreated; however, such infections could progress to trigger a number of potentially life-threatening conditions. Usually, an untreated lower urinary tract infection will eventually spread from a person's bladder to one or both of their kidneys, potentially causing permanent and irreversible damage to proper kidney function and increasing a person's risk of complete kidney failure.
A small chance exists that the infection might enter a person's bloodstream from their kidneys, resulting in a possibly fatal whole-body inflammation known as, 'sepsis.' Recurrent infections are a common complication, particularly in women who have experienced 3 or more UTI's. It is because of these serious complications that people observing early UTI-like symptoms are greatly encourage to pursue immediate medical attention.
The standard treatment for urinary tract infections is prescribed oral antibiotics taken over a typical course of 7-10 days. Medications commonly prescribed for uncomplicated UTI's can include the following:
A doctor may also prescribe a pain medication to numb the person's bladder and urethra in order to relieve burning during urination. Urinary-tract analgesics tend to cause a person's urine to turn orange or red in color. For people who experience frequent recurring infections, a doctor may make specific treatment recommendations. The recommendations may include a longer course of antibiotic treatment, a home urine test to check for infection, vaginal estrogen therapy for postmenopausal women, or a single dose of an antibiotic to be taken after sexual intercourse.
Among UTIs acquired in the hospital, approximately 75% are associated with a urinary catheter, which is a tube inserted into the bladder through the urethra to drain urine. Between 15-25% of hospitalized patients receive urinary catheters during their hospital stay. The most important risk factor for developing a catheter-associated UTI (CAUTI) is prolonged use of the urinary catheter. Catheters should only be used for appropriate indications and should be removed as soon as they are no longer needed.