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Normal urine contains no bacteria, but bacteria do cover your skin and are present in large numbers in the rectal area and in your bowel movements. Bacteria may, at times, get into the urinary tract (and the urine) and may travel up the urethra into the bladder.
When this happens, the bacteria cause infection and inflammation of the bladder. In other words, they multiply, causing irritation, swelling, and pain. Bladder infection, also called cystitis, is the most common urinary tract infection.
If the bacteria travel upward from the bladder through the ureters and reach the kidneys, you may develop a kidney infection, also known as pyelonephritis. Kidney infections are much less common but often more serious than bladder infections.
Some people, mainly women, develop urinary tract infections because they are prone to such infections the way other people are prone to getting coughs or colds. Urinary tract infections are much less common in men and children than in adult women.
A number of factors may increase a person’s risk of getting a urinary tract infection. Some of these factors include:
A urinary tract infection in a man or child may be the sign of an abnormal urinary tract. For this reason, when men or children are found to have a urinary tract infection, they may be referred to a urologist (a specialist in diseases of the urinary system and the male reproductive system) for additional tests and x-rays.
During a urinary tract infection, the lining of the bladder and urethra becomes irritated just as the inside of the nose or throat does during a cold. The irritation can cause pain in the abdomen and pelvic area and may create the constant sensation of needing to empty the bladder.
The need to urinate may seem urgent, but trying to do so may produce only a few drops of urine. In addition, there may be a burning sensation during urination. It may even be hard to control, and some urine may leak onto clothing. Sometimes the urine has an unpleasant odor or a cloudy look. At times, bladder infections may also cause low back pain, fever, or chills.
Kidney infections produce fever and back pain much more commonly than do bladder infections. If a kidney infection is not treated promptly, the bacteria may spread to the bloodstream and cause a life-threatening infection.
In an infant or young child, the signs of a urinary tract infection may not be clear, especially if the child is too young to describe just how he or she feels. Instead, the child may be irritable, not eat as much as usual, have a fever or loose bowel movements, or just not seem healthy. If the symptoms last more than a day, it is probably time to see a doctor.
Anyone noticing such symptoms in a young child should probably check with a doctor. If there is blood in the urine, a child or adult should see a doctor right away. Because bloody urine is not normally caused by an infection, it may mean a different urinary tract problem.
A doctor first looks for signs of an infection by examining urine samples under a microscope. If an infection is present, the physician may also perform a urine culture, a process in which bacteria from infected urine are grown in a laboratory.
The germs can then be identified and tested to see which drugs will provide the most effective treatment. It often takes a day or two, however, to complete this testing.
Urinary tract infections are treated with antibiotics (infection-fighting drugs), generally taken by mouth. The doctor chooses a drug formulated to treat the bacteria most likely to be causing the infection. Then, once the test results are in, the doctor may switch the patient to another antibiotic, one that is more effective against the particular bacteria found in the urine.
The number of days the patient takes the medication and the number of doses taken each day depend, in part, on the type of infection and its severity. At minimum, medication has to be taken for at least two to three days and possibly for as long as several weeks. The daily treatment schedule depends on the specific drug prescribed. It may call for a single dose each day or up to four daily doses.
A few doses of the antibiotic may relieve the need to urinate often and most of the pain from a bladder infection. It may be several days, however, before the bladder infection and its symptoms vanish completely. In any case, it is important to take medications as prescribed and not to stop them simply because the symptoms have gone away. Unless urinary tract infections are fully treated, they frequently return.
Anyone with a urinary tract infection should drink fluids whenever he or she is thirsty. It is not necessary to drink large amounts, but everyone should make certain that the body has the liquid it needs.
If the urinary tract infection is severe, it may involve the kidneys. In that case, antibiotic drugs may have to be injected. Hospital treatment with medication given intravenously (injected directly into the bloodstream) is sometimes necessary.
The following are steps to reduce the risk of a urinary tract infection:
Consult your doctor at the first sign of a problem. Urinary tract infections are very common, and they are easiest to treat if caught before they become severe or spread beyond the bladder.