Urinary Tract Infection (UTI): Symptoms, Causes, and Treatment

UTIs are bacterial infections affecting the bladder, urethra, or kidneys. Women get them more often due to anatomy. Symptoms typically include burning during urination, urgent/frequent bathroom trips, and lower abdominal discomfort. While uncomfortable, most UTIs are easily treated with antibiotics prescribed by a doctor.

In plain words

A UTI is an infection in your urinary system, which includes your kidneys, bladder, and tubes that carry urine. Most UTIs happen in the bladder. They are caused by bacteria, usually E. coli from your gut. Women get UTIs more often than men because their urethra (the tube that carries urine out) is shorter. Symptoms often include pain when you pee, needing to go often, and urine that looks cloudy or smells bad. UTIs are treated with antibiotics prescribed by a doctor. Some people get UTIs over and over again. Drinking water and peeing after sex can help prevent UTIs.

What is Urinary Tract Infection (UTI): Symptoms, Causes, and Treatment?

Symptoms

Early symptoms

Burning sensation when urinating: Pain or stinging feeling when you pee is often the first noticeable UTI sign. The discomfort may range from mild to severe. (2) (6)
Frequent urge to urinate: Feeling like you need to go constantly, even if very little urine comes out. This may disrupt sleep with nighttime bathroom trips. (2) (6)
Cloudy, dark, or bloody urine: Urine may appear murky or have a pink, red, or cola-colored tint from blood. The smell might be stronger than usual too. (2)
Pelvic pressure or discomfort: Women often feel an ache or pressure in the lower abdomen or pelvic area. Men may notice fullness in the rectum. (2) (6)
Low-grade fever: Some people develop a mild fever (under 100.4°F/38°C) with a bladder infection, though this isn't always present. (2)
Fatigue or shakiness: Your body fighting an infection may leave you feeling more tired than usual or slightly unsteady. (6)

Serious or emergency symptoms

High fever (over 100.4°F/38°C): A rising temperature may signal the infection has reached your kidneys or bloodstream. Seek medical care promptly. (5)
Back or side pain below ribs: Discomfort in your flank (between ribs and hip) on one or both sides suggests possible kidney infection. Contact a doctor within 24 hours. (5)
Nausea or vomiting: Feeling sick to your stomach or throwing up can indicate the infection is spreading. Get medical attention the same day. (5)
Confusion or dizziness: Mental changes, especially in older adults, may signal a serious infection needing urgent care. Seek emergency evaluation. (5)

Causes

Primary causes

Bacteria entering the urinary tract: Most UTIs start when bacteria (especially E. coli from the digestive tract) travel up the urethra to the bladder. (1) (6)
Sexual activity: Intercourse can introduce bacteria into the urinary tract in women. The risk increases with frequency of sexual activity. (1) (4)
Blocked urine flow: Conditions like kidney stones or an enlarged prostate that prevent complete bladder emptying allow bacteria to grow. (6)

Risk factors

Female anatomy

Women's shorter urethras allow bacteria quicker access to the bladder. The urethral opening is also closer to the anus. (1) (6)

Sexual activity

Intercourse introduces bacteria into the urinary tract. Using spermicides or diaphragms further increases risk for women. (1) (4)

Menopause

Lower estrogen levels cause urinary tract changes that make postmenopausal women more vulnerable to infection. (8)

Urinary tract blockages

Conditions like kidney stones or an enlarged prostate that prevent complete bladder emptying increase infection risk. (6) (8)

Diagnosis

Doctors typically diagnose UTIs by reviewing your symptoms and testing a urine sample. A urinalysis checks for white blood cells, red blood cells, or bacteria. Sometimes a urine culture is done to identify specific bacteria and determine which antibiotics will work best. For recurrent UTIs, your doctor may recommend imaging tests to check for structural issues in your urinary tract.

Urinalysis

Checks urine for signs of infection like white blood cells, red blood cells, or bacteria. (6)

Urine culture

Identifies the exact bacteria causing infection and which antibiotics can treat it effectively. (6)

Imaging tests (if needed)

Ultrasound, CT scan, or MRI may be used if you have recurrent UTIs to check for structural problems. (6)

Treatment

Medication options

Antibiotics

These medications kill the bacteria causing your infection. Your doctor will choose one based on your health history and local antibiotic resistance patterns. (1) (3)

Pain relievers

This medication soothes bladder irritation and reduces pain during urination while antibiotics work. (3)

Lifestyle and self-care

Drink plenty of water: Staying well-hydrated helps flush bacteria from your urinary tract. Aim for at least six to eight glasses daily when you have an infection. (3) (4)
Urinate when needed: Don't hold urine for long periods. Going when you feel the urge helps prevent bacterial buildup. (4)
Wipe front to back: This hygiene practice (especially for women) helps prevent bacteria from the anal area spreading to the urethra. (4)
Empty your bladder after sex: Urinating shortly after intercourse helps flush out bacteria that may have entered the urethra. (4)

Always discuss dosing and treatment changes with your own prescriber.

Possible complications

Recurrent infections: Some people experience multiple UTIs within a year — defined as two infections in six months or three in one year. (8)
Kidney infection: An untreated UTI can spread upward to one or both kidneys, potentially causing permanent damage if not treated promptly. (5) (8)
Sepsis: A rare but life-threatening complication where infection spreads to the bloodstream, requiring emergency hospital care. (5)
Narrowed urethra (in men): Repeated UTIs in men can sometimes lead to scarring and narrowing of the urethra over time. (6)

When to see a doctor

Routine follow-up

Schedule an appointment if you experience painful urination, frequent urges to go, cloudy urine, or pelvic discomfort that lasts more than a day. (2)
See your doctor if UTI symptoms return after treatment, as this may indicate an underlying issue needing further evaluation. (8)

Seek emergency care

Seek immediate care for fever over 100.4°F (38°C) with UTI symptoms, shaking chills, nausea, vomiting, or severe back/side pain. (5)
Get emergency help if you develop confusion, dizziness, or difficulty breathing along with UTI symptoms — possible signs of sepsis. (5)

Frequently asked questions

How do you know if you have a UTI?

Common signs include a strong, persistent urge to urinate, pain or burning when peeing, passing small amounts frequently, and urine that looks cloudy or smells strong. Some people also notice pelvic pressure or mild fever. If you have these symptoms, check with your doctor. (2) (6)

Can a UTI go away on its own?

Some mild UTIs may clear up with increased fluids, but most require antibiotics. Since the infection can spread to your kidneys without treatment, it's safest to consult a doctor when symptoms develop. (1) (3)

What causes recurrent UTIs?

Frequent UTIs can result from incomplete treatment of previous infections, new bacterial exposure, anatomical differences, decreased estrogen after menopause, or underlying medical conditions. If you get multiple UTIs, talk with your doctor about prevention strategies. (8) (3)

When is a UTI an emergency?

Seek immediate care if you develop high fever, shaking chills, nausea/vomiting, severe back/side pain, confusion, or difficulty breathing with UTI symptoms — these may indicate kidney infection or sepsis requiring urgent treatment. (5)

Do cranberries help a UTI?

Cranberry products might help prevent UTIs by making it harder for bacteria to stick to urinary tract walls, but research results are mixed. While cranberry juice or supplements won't hurt, they shouldn't replace medical treatment for active infections. (7) (4)

References

CDC — Urinary Tract Infection source 1
NHS — Urinary tract infections (UTIs) - Symptoms source 2
NHS — Urinary tract infections (UTIs) - Treatment source 3
NHS — Urinary tract infections (UTIs) - Prevention source 4
NHS — Urinary tract infections (UTIs) - When to get medical advice source 5
MedlinePlus — Urinary Tract Infections source 6
MedlinePlus — Cranberry source 7
CDC — Recurrent Urinary Tract Infections source 8