Most urinary tract infections are caused by bacteria that enter the urethra and then the bladder. The infection most commonly develops in the bladder, but can spread to the kidneys. Most of the time, your body can get rid of these bacteria. However, certain conditions increase the risk of having UTIs.
Women tend to get them more often because their urethra is shorter and closer to the anus than in men. Because of this, women are more likely to get an infection after sexual activity or when using a diaphragm for birth control. Menopause also increases the risk of a UTI.
The following also increase your chances of developing a UTI:
Your health care provider must first decide if the infection is just in the bladder or has spread to the kidneys and how severe it is.
MILD BLADDER AND KIDNEY INFECTIONS
Most of the time you will need to take antibiotic to prevent the infection from spreading to the kidneys.
For a simple bladder infection, you will take antibiotics for 3 days (women) or 7 - 14 days (men).
For a bladder infection with complications -- such as pregnancy or diabetes, OR a mild kidney infection -- you will usually take antibiotics for 7 - 14 days.
Be sure to finish all of the antibiotics, even if you feel better. If you do not finish the whole dose of medicine, the infection may return and be harder to treat later.
Always drink plenty of water when you have a bladder or kidney infection.
Commonly used antibiotics include trimethoprim-sulfamethoxazole, amoxicillin, Augmentin, doxycycline, and fluoroquinolones. (Tell your health care provider if you might be pregnant before taking these drugs.)
RECURRENT BLADDER INFECTIONS
Some women have repeated bladder infections. Your health care provider may suggest that you:
Take a single dose of an antibiotic after sexual contact.
Have a 3-day course of antibiotics at home to use if you develop an infection.
Take a single, daily dose of an antibiotic to prevent infections.
MORE SEVERE KIDNEY INFECTIONS
You may need to go into the hospital if you are very sick and cannot take medicines by mouth or drink enough fluids. You may also be admitted to the hospital if you:
Have kidney stones or changes in the anatomy of your urinary tract
Have recently had urinary tract surgery
Have cancer, diabetes, multiple sclerosis, spinal cord injury, or other medical problems
Are pregnant and have a fever or are otherwise ill
At the hospital, you will receive fluids and antibiotics through a vein.
Some people have urinary tract infections that do not go away with treatment or keep coming back. These are called chronic UTIs. If you have a chronic UTI, you may need stronger antibiotics or take medicine for a longer time.
You may need surgery if the infection is caused by a problem with the structure of the urinary tract.
Most urinary tract infections can be treated successfully. Bladder infection symptoms usually go away within 24 - 48 hours after treatment begins. If you have a kidney infection, it may take 1 week or longer for symptoms to go away.
Life-threatening blood infection (sepsis). The risk is greater among the young, very old adults, and those whose bodies cannot fight infections (for example, due to HIV or cancer chemotherapy)
Kidney damage or scarring
Calling your health care provider
Contact your health care provider if you have symptoms of a UTI. Call right away if have signs of a possible kidney infection such as:
Back or side pain
Also call if UTI symptoms come back shortly after you have been treated with antibiotics.
Diet and lifestyle changes may help prevent some UTIs. After menopause, a woman may use estrogen cream around the vagina to reduce infections.
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Gupta K, Hooton TM, Naber KG, et al. International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: A 2010 update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases. Clin Infect Dis. 2011 Mar;52(5):e103-20.
Hooton TM, Bradley SF, Cardenas DD, et al. Diagnosis, prevention, and treatment of catheter-associated urinary tract infection in adults: 2009 International Clinical Practice Guidelines from the Infectious Diseases Society of America. Clin Infect Dis. 2010 Mar 1;50(5):625-63.
Jepson RG, Williams G, Craig JC. Cranberries for preventing urinary tract infections. Cochrane Database of Systematic Reviews. 2012;10:CD001321. DOI: 10.1002/14651858.CD001321.pub5.
Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.