What Is It?
Urinary tract infections involve the parts of the body — the kidneys, ureters, bladder and urethra — that produce urine and carry it out of the body. Urinary tract infections often are classified into two types based on their location in the urinary tract:
- Lower tract infections — These include cystitis (bladder infection) and urethritis (infection of the urethra). Lower urinary tract infections commonly are caused by intestinal bacteria, which enter and contaminate the urinary tract from below, usually by spreading from the skin to the urethra and then to the bladder. Urethritis also may be caused by microorganisms that are transmitted through sexual contact, including gonorrhea and Chlamydia. Another form of male urinary infection is prostatitis which is an inflammation of the prostate.
- Upper tract infections — These involve the ureters and kidneys and include pyelonephritis (kidney infection). Upper tract infections often occur because bacteria have traveled upward in the urinary tract from the bladder to the kidney or because bacteria carried in the bloodstream have collected in the kidney.
Most cases of urinary tract infections occur in women. Of those that occur in men, relatively few affect younger men. In men older than 50, the prostate gland (a gland near the bottom of the bladder, close to the urethra) can enlarge and block the flow of urine from the bladder. This condition is known as benign prostatic hyperplasia or BPH. This condition can prevent the bladder from emptying completely, which increases the likelihood that bacteria will grow and trigger an infection. Cystitis is more common in men who practice anal intercourse and in those who are not circumcised. Other factors that increase the risk of urinary infections include an obstruction, such as that caused by a partial blockage of the urethra known as a stricture, and non-natural substances, such as rubber catheter tubes (as may be inserted to relieve a blockage in the urethra).
A urinary tract infection usually causes one or more of the following symptoms:
- Unusually frequent urination
- An intense urge to urinate
- Pain, discomfort or a burning sensation during urination
- Awakening from sleep to pass urine
- Pain, pressure or tenderness in the area of the bladder (in the middle of the lower abdomen, below the navel)
- Bedwetting in a person who usually had been dry at night
- Urine that looks cloudy or smells foul
- Fever, with or without chills
- Nausea and vomiting
- Pain in the side or upper back
Your doctor will ask about your symptoms and about any previous episodes of urinary tract infection. To fully assess your risk factors, your doctor may ask about your sexual history, including your history and your partner's history of sexually transmitted diseases, condom use, multiple partners and anal intercourse.
Your doctor will diagnose a urinary tract infection based on your symptoms and the results of a physical examination and laboratory tests of your urine. In a typical urinary tract infection, your doctor will see both white blood cells (infection-fighting cells) and bacteria when he or she examines your urine under a microscope. Your doctor probably will send your urine to a laboratory to identify the specific type of bacteria and specific antibiotics that can be used to eliminate the bacteria.
In men, a rectal examination will allow your doctor to assess the size and shape of the prostate gland. If you are a young man with no sign of an enlarged prostate, your doctor may order additional tests to search for a urinary tract abnormality that increases the likelihood of infection. This is because urinary tract infections are relatively rare in young men with normal urinary tracts. Additional tests may include intravenous pyelography or a computed tomography (CT) scan, which shows an outline of your urinary tract on X-rays; ultrasound; or cystoscopy, an examination that allows your doctor to inspect the inside of your bladder using a thin, hollow tube-like instrument.
With proper treatment, most uncomplicated urinary tract infections begin to improve in one to two days.
Most urinary tract infections in men cannot be prevented. Practicing safe sex by using condoms will help to prevent infections that are transmitted through sexual contact.
In men with benign prostatic hypertrophy, cutting out caffeine and alcohol or taking certain prescription medications may help to improve urine flow and prevent the buildup of urine in the bladder, which increases the likelihood of infection. Many men with urinary infections due to an enlarged prostate gland require surgery to remove part of the gland. Because this surgery can improve urine flow, it can help prevent infections.
Doctors treat urinary tract infections with a variety of antibiotics. The results of laboratory tests on your urine can help your doctor pick the best antibiotic for your infection. In general, most uncomplicated lower tract infections will be eliminated completely by five to seven days of treatment. Once you finish taking the antibiotics, your doctor may ask for a repeat urine sample to check that bacteria are gone. If an upper tract infection or infection of the prostate is diagnosed, your doctor may prescribe antibiotics for three weeks or longer.
Men with severe upper tract infections may require hospital treatment and antibiotics given through an intravenous catheter (in a vein). This is especially true when nausea, vomiting and fever increase the risk of dehydration and prevent the use of oral antibiotics.
When To Call a Professional
Call your doctor whenever you have any of the symptoms of a urinary tract infection.
If you are approaching age 50, call your doctor if you notice any of the following: a decrease in the force of your urine stream, difficulty in beginning urination, dribbling after you urinate, or a feeling that your bladder isn't totally empty after you finish urinating. These could be symptoms of an enlarged prostate, a problem that can be treated effectively before it triggers a urinary tract infection.
Most urinary tract infections can be treated easily with antibiotics. In a man who has a urinary tract abnormality or an enlarged prostate, repeated urinary tract infections may occur as long as the underlying problem continues to interfere with the free flow of urine.
National Institute of Diabetes & Digestive & Kidney Disorders
Urology Care Foundation