Urinary tract infections
- What are UTIs?
- What is the urinary tract?
- What causes infection?
- What are the symptoms?
- How are UTIs diagnosed?
- How are they treated?
- Can UTIs be prevented?
What are UTIs?
Urinary tract infections are more commonly known as UTIs. Infections of the urinary tract are extremely common in Ireland and account for a large proportion of doctor visits per year.
UTIs are particularly common among women, and it is estimated that as many as one in every five women will develop some form of UTI during her lifetime. UTIs are less common in men and this is believed to be due to the longer urethra (the tube draining the bladder) in men.
What is the urinary tract?
The four key elements of the urinary system are the kidneys, ureters (tubes connecting the kidneys and bladder), bladder and urethra (tube draining the bladder).
Purplish-brown in colour, the kidneys are located just below the ribs in the flanks and perform a number of vital functions. They remove liquid waste from the blood in the form of urine; keep a stable balance of salts and other substances in the blood and produce a hormone that aids the formation of red blood cells (erythropoetin).
The narrow tubes which connect the kidneys to the bladder are called ureters. Their function is to carry the urine from the kidneys to the bladder where it is stored before being emptied through the urethra. The bladder is a muscular organ, shaped like a triangle that is located in the lower abdomen.
While varying amounts of urine are passed by adults each day, depending on their intake of fluids, the average adults passes about a quart and a half of urine each day. The production of urine slows down at night to about half of the daytime figure.
What causes infection?
Normal urine contains fluids, salts and waste products, and it is always sterile (contains no bacteria). An infection commonly occurs when micro-organisms enter through the external opening (the urethra) and begin to multiply. The majority of UTIs are caused by one type of bacteria, Escherichia coli (E. coli), which normally reside in the colon. Infections can also be carried to the urinary tract through the bloodstream, although this is much less common.
An infection which is limited to the urethra is called urethritis. If the infection moves up to through the urethra to the bladder it causes a bladder infection, which is known as cystitis. If the infection is not treated promptly and is allowed to travel along the urethers and into the kidneys it causes a potentially serious condition known as pyelonephritis.
There are other micro-organisms which can causes UTIs in both men and women, some of whom which are sexually transmitted. Sexually transmitted infections are usually caused by chlamydia or mycoplasma. If a person becomes infected with a sexually transmitted infection, all sexual partners should also be treated to prevent the spread of the infection.
Among the other risk factors for the development of UTIs are:
- Obstruction of the urinary tract: a kidney stone, for example, will obstruct the natural flow of urine from the urinary tract and may be the focus for an infection. Similarly, an enlarged prostate gland in men will also increase the likelihood of infection.
- Catheters: a catheter is a tube which is placed in the bladder to drain urine when the patient is unable to perform this vital function themselves. It is used in cases where a patient may be unconscious, after surgery, and especially among the elderly who have lost natural bladder control. Prolonged use of catheters is one of the most common causes of UTIs and the highest levels of hygiene must be observed by medical staff at all times in the handling of catheters.
- The use of diaphragms: several studies have concluded that women who use a diaphragm are much more likely to develop UTIís than those who use other forms of contraception.
UTIs are relatively uncommon in boys and men and are frequently associated with an identifiable underlying cause, such as an enlarged prostate gland. UTIs are much commoner in females of every age, often without any identifiable underlying cause. One of the reasons for this is that the female urethra urethra is short, allowing bacteria to gain access to the bladder very easily. In addition, the female urethra is located very close to other potential sources of bacterial infection from the vagina and the anus.
What are the symptoms?
Symptoms of UTIs are wide ranging and include:
- An intense urge to urinate all the time, even though very little urine may be passed.
- Pain, discomfort and a burning sensation on urination.
- Urine that looks cloudy, may have traces of blood in it, or has an unusually strong and offensive smell.
- In severe cases of UTI, there may be bedwetting at night, even among adults,
- Fever, and a general feeling of being unwell. There may also be nausea and vomiting, particularly in children.
- Pain in the side or lower back.
How are UTIs diagnosed?
Your GP will make a diagnosis on the basis of your symptoms and will also examine a mid-stream sample of urine which must be collected in a sterile container. This sample may be sent for laboratory analysis to identify the type of bacteria of the urinary tract.
UTIs tend to be more common among pregnant women, and they must be treated promptly to avoid the development of an infection in the kidneys (pyelonephritis) which may have serious consequences.
How are they treated?
Cystitis (inflammation of the bladder) may cause the same symptoms as an infection in the bladder. Inflammation may be treated by increasing the amount of fluid taken and taking medication to reduce the acidity of the urine.
If a definite infection is present or symptoms persist for more than 72 hours, antibiotics may be prescribed. Short courses of antibiotics (three or five days) are usually sufficient to clear an infection from the bladder. It is important to finish the course of antibiotics as prescribed to prevent the development of resistant bacteria.
If the infection has travelled into the kidneys, a longer course of antibiotics will be required and hospitalisation may be required in more severe cases, especially if there is nausea, vomiting and high fever.
Can UTIs be prevented?
Some forms of urinary tract infection can not be prevented, but there are some simple steps which everyone, and particularly women, can take to reduce their risk of contracting this uncomfortable condition. These include:
Drink plenty of fluids each day: Fluids prevent the growth of bacteria because they keep the urinary tract flushed out. All fluids are good, but cranberry juice and other drinks which are very high in Vitamin C have been claimed to be particularly effective in keeping the urine sterile.
Toilet hygiene: after using the toilet, always wipe from front to back to prevent the spread of bacteria (especially E. coli) from the anus to the vaginal area where it can gain quick access to the external opening (the urethra).
Sexual hygiene: Women who are prone to UTIs should always urinate after sexual intercourse to flush out bacteria which may have entered the urethra or bladder. It is also a very good policy to wash the entire area around the genitals and anus before intercourse, and this advice applies to both men and women.
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