What Is It?
A urinary tract infection is an infection involving the organs that produce urine and carry it out of the body. These structures include the kidneys, ureters (long, slender tubes connecting the kidneys with the bladder), bladder and urethra. Doctors often divide urinary tract infections into two types, lower tract infections and upper tract infections:
Women are affected much more often than men because women have short urethras that allow relatively easy passage of bacteria into the bladder. Sexually active women are especially prone to bladder infections. Sexual intercourse can cause bacteria to spread upward into the bladder. Also, the use of contraceptive diaphragms and spermicides may change the normal bacterial environment around the urethra and make infection more likely. In pregnant women, temporary changes in the physiology and anatomy of the urinary tract make expectant mothers prime candidates for cystitis and pyelonephritis. Kidney and bladder infections can pose a serious risk to pregnant women and their unborn children, because they increase the risk of premature contractions or delivery and sometimes death of the fetus or newborn infant.
Lower and upper tract infections can cause one or more of the following symptoms:
Your doctor will ask you about your symptoms and whether you have had a urinary tract infection before. He or she also will ask you about your sexual history, including any history of sexually transmitted diseases for yourself and your partner, condom use, multiple partners, use of diaphragm and/or spermicides and whether you could be pregnant. Your doctor also will ask if you have any other medical problems, such as diabetes, which can make you more likely to develop infections.
You will be asked to give a urine sample, which will be tested to see if it contains bacteria or other signs of infection. Your urine also may be sent to the laboratory to identify the specific type of bacteria and the specific antibiotics that can be used to eliminate the bacteria. If you have a fever or other symptoms of an upper tract infection, your doctor may order a blood test to determine your white blood cell count. A high white cell count indicates infection. The blood can also be tested for bacterial growth. This is called a blood culture.
In people with symptoms of a severe kidney infection or frequent episodes of lower or upper urinary tract infections, additional testing may be needed, such as:
With proper treatment, most uncomplicated urinary tract infections can be cured in two to three days. It may take several days for the symptoms of a kidney infection to completely go away.
To help prevent urinary tract infections:
Doctors treat lower and upper urinary tract infections with antibiotics. Laboratory testing can determine the best antibiotic for treatment. Most uncomplicated lower tract infections are treated with a three-day course of antibiotics, although women who are pregnant, or who have diseases such as diabetes that suppress the immune system, usually need to take antibiotics for longer.
People with upper tract infections are usually treated with a 10- to 14-day course of antibiotic therapy. Those with severe upper tract infections may require hospital treatment with antibiotics given through a vein (intravenously). This is especially true if nausea, vomiting and fever increase the risk of dehydration and prevent the person from taking oral antibiotics.
When To Call a Professional
Call your doctor if you have frequent urination, an intense urge to urinate, discomfort during urination or other symptoms of a urinary tract infection. You also should seek prompt medical attention if you have symptoms of a kidney infection, such as fever, nausea, vomiting and pain in the side or back. It is especially important for any pregnant woman who has symptoms of an upper or lower urinary tract infection to call her doctor immediately.
Once a woman has been cured of cystitis, she has a 20% chance of developing a second infection. After the second infection, she has a 30% risk of developing a third. If a woman has three or more episodes of cystitis within 1 year and the structure or anatomy of the urinary tract is normal, her doctor may prescribe a special antibiotic regimen to decrease the risk of future infections.
National Institute of Diabetes & Digestive & Kidney Disorders
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American Urological Association
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Linthicum, MD 21090