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Urinary tract infection - adults

  • Alternative Names

    Bladder infection - adults; UTI - adults; Cystitis - bacterial - adults; Pyelonephritis - adults; Kidney infection - adults


    Your doctor must first decide whether you have a mild or simple bladder or kidney infection, or whether your infection is more serious.


    Antibiotics taken by mouth are usually recommended because there is a risk that the infection can spread 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.
    • It is important that you finish all the antibiotics, even if you feel better. If you do not finish all your antibiotics, the infection could return and may be harder to treat.

    Commonly used antibiotics include trimethoprim-sulfamethoxazole, amoxicillin, Augmentin, doxycycline, and fluoroquinolones. Your doctor will also want to know whether you could be pregnant.

    Your doctor may also recommend drugs to relieve the burning pain and urgent need to urinate. Phenazopyridine hydrochloride (Pyridium) is the most common of this type of drug. You will still need to take antibiotics.

    Everyone with a bladder or kidney infection should drink plenty of fluids.

    Some women have repeat or recurrent bladder infections. Your doctor may suggest several different ways of treating these.

    • Taking a single dose of an antibiotic after sexual contact may prevent these infections, which occur after sexual activity.
    • Having a 3-day course of antibiotics at home to use for infections diagnosed based on your symptoms may work for some women.
    • Some women may also try taking a single, daily dose of an antibiotic to prevent infections.

    See also: Catheter-associated UTI


    If you are very sick and cannot take medicines by mouth or drink enough fluids, you may be admitted to the hospital. You may also be admitted to the hospital if you:

    • Are elderly
    • 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 keep coming back or that do not go away with treatment. Such infections are called chronic UTIs. If you have a chronic UTI, you may need antibiotics for many months, or stronger antibiotics may be prescribed.

    If a structural (anatomical) problem is causing the infection, surgery may be recommended.

    Support Groups

    Expectations (prognosis)

    A urinary tract infection is uncomfortable, but treatment is usually successful. Symptoms of a bladder infection usually disappear within 24 - 48 hours after treatment begins. If you have a kidney infection, it may take 1 week or longer for your symptoms to go away.

    • Life-threatening blood infection (sepsis) - 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
    • Kidney infection

    Calling your health care provider

    Contact your health care provider if you have symptoms of a UTI. Call right away if the following symptoms develop:

    • Back or side pain
    • Chills
    • Fever
    • Vomiting

    These may be signs of a possible kidney infection.

    Also call if you have already been diagnosed with a UTI and the symptoms come back shortly after treatment with antibiotics.