The symptoms are different depending on where the infection is.

Symptoms of a UTI in the bladder include:

• Pain or burning when you urinate.
• An urge to urinate often, but usually passing only small amounts of urine.
• Pain in the lower belly.
• Urine that looks cloudy, is pink or red, or smells bad.

Symptoms of a UTI in the kidneys include:

• Pain in the flank. This is felt just below the rib cage and above the waist on one or both sides of the back.
• Fever and chills.
• Nausea and vomiting.

Some people have bacteria in their urinary tract without having any symptoms. This is called asymptomatic bacteriuria. It may lead to infections that cause symptoms, but in many cases it doesn't. It usually goes away without treatment.

Several other conditions, such as vaginal infections or an irritable bladder, can cause symptoms like those of a UTI.