Condition guide
Urinary Tract Infections (UTIs)
Also known as: UTI, Cystitis, Bladder infection, Pyelonephritis
In brief
A urinary tract infection (UTI) is an infection of the bladder, kidneys, ureters or urethra, usually caused by bacteria. Most bladder infections respond quickly to antibiotics, but recurrent infections, infections in men and kidney infections deserve a careful assessment.
Medically reviewed by Dr. Atip Chatsudthipong, MD on
Written by Editorial teamPublished Updated
What is a urinary tract infection?
A UTI occurs when bacteria — most often from the bowel — enter the urinary tract and multiply. An infection of the bladder is called cystitis; an infection that travels up to the kidney is called pyelonephritis and is more serious.
UTIs are much more common in women because the urethra is shorter. In men, UTIs are less common and are generally considered "complicated", so they usually warrant further evaluation.
What are the symptoms of a UTI?
Bladder infection (cystitis)
- Burning or pain when passing urine
- Needing to urinate frequently or urgently, often passing only small amounts
- Discomfort or pressure in the lower abdomen
- Cloudy, strong-smelling or blood-stained urine
Kidney infection (pyelonephritis)
- Fever, chills or shivering
- Pain in the side or back
- Nausea or vomiting
- Feeling generally unwell
What increases the risk of UTIs?
- Sexual activity and some forms of contraception, such as spermicides
- Menopause, due to changes in the vaginal and urethral tissues
- Incomplete bladder emptying — for example due to prostate enlargement or nerve conditions
- Kidney stones or other blockages
- Urinary catheters
- Diabetes and conditions that weaken the immune system
- Pregnancy
How are UTIs diagnosed?
A urine test can show signs of infection, and a urine culture identifies the bacteria and which antibiotics will work. A culture is particularly important for recurrent infections, infections in men, and infections that do not settle with initial treatment.
For recurrent or complicated UTIs, a urologist may recommend an ultrasound to check bladder emptying and look for stones or blockage, and in selected cases a CT scan or cystoscopy. Routine imaging and cystoscopy are not needed for every woman with uncomplicated recurrent UTIs.
How are UTIs treated and prevented?
Most bladder infections are treated with a short course of antibiotics chosen according to local resistance patterns and, ideally, the culture result. Kidney infections need longer treatment and sometimes hospital care.
Reducing recurrent infections
- Drinking enough fluid through the day
- Vaginal estrogen for peri- and post-menopausal women, which reduces the risk of recurrence
- Treating underlying causes such as stones or incomplete bladder emptying
- Cranberry products, which may help some women
- Preventive (prophylactic) antibiotics or non-antibiotic options in selected cases, balanced against the risk of antibiotic resistance
When should you seek medical attention?
Seek urgent medical care if you have:
- Fever, chills, back or side pain, or vomiting with urinary symptoms
- Confusion, dizziness or feeling very unwell — signs that infection may be spreading
- Urinary symptoms during pregnancy
- A UTI together with a known kidney stone
Consider a urology consultation if you have repeated infections, infections that do not clear, blood in the urine that persists after treatment, or if you are a man with a UTI.
How Dr. Atip can help
Dr. Atip can review your history and previous culture results, look for treatable causes and create a prevention plan suited to you — with the aim of reducing infections while using antibiotics responsibly.
Frequently asked questions
Can a UTI go away on its own?
Some mild bladder infections in otherwise healthy women may settle without antibiotics, but untreated infections can spread to the kidneys. Anyone with fever, back pain or worsening symptoms should seek medical care promptly.
Why do I keep getting UTIs?
Recurrent UTIs can be linked to sexual activity, menopause, incomplete bladder emptying, stones or other factors. In many women no structural cause is found. An assessment helps identify contributing factors and the most suitable prevention strategy.
Should men with a UTI see a urologist?
Usually, yes. UTIs are uncommon in men and may be associated with prostate enlargement, incomplete bladder emptying, stones or prostate infection, so further evaluation is generally recommended.
References
- 1.Anger J, et al. Recurrent Uncomplicated Urinary Tract Infections in Women: AUA/CUA/SUFU Guideline. J Urol. 2019;202(2):282–289. (opens in a new tab)
- 2.European Association of Urology. EAU Guidelines on Urological Infections. (opens in a new tab)
- 3.NIDDK. Bladder Infection (Urinary Tract Infection — UTI) in Adults. (opens in a new tab)
This information is for general education and does not replace a consultation with a qualified doctor. If you have severe symptoms, seek emergency care (in Thailand, call 1669). See our medical disclaimer.