What Is a Urinary Tract Infection (UTI)?

"Why does it sting every time I go — and why do I keep needing to go again five minutes later?" If you've ever asked that in a pharmacy queue, you've probably met a urinary tract infection. A UTI is an infection somewhere along the urinary tract — the urethra, bladder, ureters, or kidneys. The short video above, "Urinary Tract Infection" (about two and a half minutes), walks through the tell-tale signs to keep an eye out for, and it's a useful checklist to hold in mind as you read on.

Where exactly is the infection?

Most UTIs stay low, in the bladder and the urethra — the tube urine leaves by. That lower infection is what people usually mean by cystitis, or a bladder infection. Bacteria that normally live harmlessly around the bowel and skin can reach the urethra and travel upward, and because the urethra is shorter in women, UTIs are much more common in women — though men and children get them too. If bacteria climb further, to a ureter or a kidney, the infection becomes more serious; that higher infection tends to bring fever and pain in the back or side, and it needs prompt medical care rather than a wait-and-see approach.

What does a UTI actually feel like?

The video above names the classic pattern plainly: a burning feeling when you urinate, and a frequent or intense urge to go even though little comes out when you do. Add to that list cloudy or strong-smelling urine, a sense of pressure low in the pelvis, and sometimes a dull ache in the lower abdomen. Symptoms can arrive quite suddenly — fine in the morning, uncomfortable by evening — which is one reason UTIs catch people off guard. In older adults the picture can be less tidy, with new confusion or unusual tiredness sometimes the first clue, so a sudden change like that is worth mentioning to a clinician rather than brushing off.

How will a doctor know it's really a UTI?

Usually it starts with your story plus a urine sample. A quick dipstick test in the clinic looks for signs of inflammation and bacteria, and the sample can also be sent to a laboratory, where growing the bacteria identifies exactly which organism is responsible — helpful if an infection keeps coming back or doesn't settle. That distinction matters because not every burning sensation is an infection, and similar symptoms can come from irritation or from other urinary problems, such as a kidney stone higher up the tract. Getting the cause right is what guides the right treatment.

And how is it treated?

Because most UTIs are bacterial, treatment usually centres on an antibiotic chosen by your clinician, alongside drinking normally and not putting off trips to the toilet. A companion video on this site, "Urinary Tract Infection Treatment", explains how these infections of the urethra, bladder, ureters, or kidneys are approached. Symptoms often start easing within a day or two of starting treatment, but the course your clinician prescribes should still be finished as directed, and you should go back if things aren't improving. Seek care promptly — same day — if you develop fever, shivering, vomiting, or pain in your back or side, if you see blood in your urine, if you're pregnant, or if symptoms keep returning; those are signs the infection may be higher up or need a closer look.

MedicalVideos.com has published trusted medical videos since 2007. The site was founded by Dr. Mohamed Ibrahim, MD, PhD — physician and researcher.

Educational only — this article is general information about urinary tract infections, not medical advice and not a diagnosis. If you have urinary symptoms, fever, or back or side pain, contact a clinician for assessment.

Frequently Asked Questions

What causes most UTIs?

Most are caused by bacteria — very often E. coli from the bowel — reaching the urethra and multiplying in the bladder. They are not usually caught from another person.

Can a UTI clear up on its own?

Occasionally a very mild lower infection settles without treatment, but UTIs can also worsen or spread upward to the kidneys. Because you can't tell in advance which way it will go, symptoms are best assessed by a clinician.

Why do some people get UTIs again and again?

Recurrences can follow anatomy, incomplete emptying of the bladder, or simply the way bacteria reach the urethra. If infections keep returning, a clinician may send urine for laboratory culture and look for an underlying reason.

Is cranberry juice a treatment for a UTI?

No — it is not a treatment for an active infection. Some people use cranberry products hoping to reduce recurrences, but a UTI that has already started needs medical assessment.

When is a UTI an emergency?

Fever, shivering, vomiting, pain in the back or side under the ribs, blood in the urine, or symptoms during pregnancy all warrant prompt, same-day medical care.