What is a urinary tract infection (UTI)?

A urinary tract infection (UTI) happens when bacteria enter the urinary system and begin to grow. This system includes the kidneys, bladder, ureters, and urethra.

UTIs are very common and can affect anyone, but they are more likely to occur in women. Most infections involve the bladder, but more serious cases can spread to the kidneys.

Symptoms

UTIs can cause a range of uncomfortable symptoms that often come on quickly.

Common symptoms include:

• A strong, frequent urge to urinate
• Burning or pain when urinating
• Cloudy, dark, or strong-smelling urine
• Blood in the urine
• Pressure or discomfort in the lower abdomen
• Pain in the back or side (possible kidney involvement)
• Fever or chills
• Nausea or vomiting

Older adults may also experience confusion or unusual fatigue.

What causes UTIs?

Most UTIs are caused by bacteria, usually E. coli, that enter the urinary tract through the urethra. These bacteria normally live in the digestive system but can spread and multiply in the urinary system.

Risk factors include:

• Female anatomy (shorter urethra)
• Sexual activity
• Not emptying the bladder fully
• Kidney stones or other blockages
• Dehydration
• Use of urinary catheters

How is it diagnosed?

A healthcare provider will begin by reviewing your symptoms and medical history.

Testing typically includes a urine sample to check for bacteria, blood, or signs of infection. A urine culture may also be done to identify the exact bacteria and choose the most effective antibiotic.

If infections happen often or are severe, imaging tests such as an ultrasound or CT scan may be used to look for structural issues. In some cases, a cystoscopy may be recommended to examine the bladder more closely.

How is it treated?

Treatment usually starts with antibiotics to clear the infection. Most people begin to feel better within a few days, but it’s important to finish the full course of medication.

Additional treatments may include:

• Medication to ease pain or burning
• Drinking plenty of water helps flush bacteria
• Avoiding bladder irritants like caffeine and alcohol

For people who experience frequent UTIs, providers may recommend preventive strategies such as lifestyle changes or low-dose antibiotics.

With prompt treatment, most UTIs resolve quickly. Delaying care can allow the infection to spread, so early treatment is important.