Concerned about your kidney health or your blood-test results?
Message our care team on WhatsApp. Tell us what’s going on and we’ll help you find the right best nephrologist — free, with no obligation.
Chat with our care team on WhatsAppNot sure who to see? Find the right specialist →
In a medical emergency, or for severe or sudden symptoms such as breathing difficulty, chest pain, fainting or stroke signs, call 995 immediately.
At a glance
- A urinary tract infection (UTI) is an infection of the bladder, urethra or kidneys, usually caused by bacteria.
- Bladder infections cause burning on urination, urgency and frequency.
- UTIs are far more common in women, though they also affect men and children.
- Most are easily treated with antibiotics, but a kidney infection is more serious.
Go to A&E or call 995 if a person with a UTI develops signs of a serious infection or sepsis: new confusion or drowsiness, a very fast heartbeat or breathing, shivering with a high fever, severe illness, little or no urine passing, or feeling that they might collapse. See a doctor the same day for fever, chills, back or side (loin) pain, vomiting, blood in the urine, or a UTI in pregnancy, in men, in young children, in anyone with a urinary catheter, or when symptoms are not improving.
What a UTI is
A urinary tract infection is an infection anywhere in the urinary system — the kidneys, the tubes that carry urine (ureters), the bladder and the urethra. Most UTIs are lower-tract infections affecting the bladder (cystitis) or the urethra (urethritis). These are common and, in otherwise healthy people, usually easily treated. An infection that travels up to the kidneys (pyelonephritis) is less common but more serious, because the kidneys are vital organs and the infection can spread into the bloodstream. Understanding which part of the tract is involved helps explain why a simple bladder infection is treated quite differently from one that reaches the kidneys.
Symptoms of a bladder or lower UTI
A lower (bladder) UTI typically causes burning or stinging on urination, a frequent and urgent need to pass urine, and passing only small amounts each time despite the urge. Urine may look cloudy, smell strong or unpleasant, or contain blood. Many people also feel a dragging discomfort or pressure low in the tummy, just above the pubic bone. These symptoms are uncomfortable but, on their own, usually reflect an infection confined to the bladder rather than a serious illness.
Symptoms that suggest a kidney infection or something more serious
Certain symptoms point to an infection that has reached the kidneys or is becoming serious, and these need prompt medical care. Warning signs include fever and shaking chills, pain in the back or side (the flank, below the ribs), feeling generally very unwell, and nausea or vomiting. When these appear alongside urinary symptoms, the infection is no longer a simple bladder problem. New confusion, a racing heart or rapid breathing, or passing very little urine can signal that the infection is spreading through the body and warrant emergency assessment.
UTIs in different groups
UTIs are far more common in women because the female urethra is shorter and closer to the bowel, giving bacteria a shorter path to the bladder. In older people, the usual burning and urgency may be absent, and the main change can instead be new confusion, agitation, drowsiness or unsteadiness — so a UTI should be considered when an older adult suddenly seems different. UTIs in men are less common and are treated as potentially complicated, since they may relate to the prostate or the urinary tract, and usually warrant assessment. A UTI in pregnancy needs prompt review because it can affect both mother and baby, even when symptoms seem mild. In children, symptoms can be vague — fever, irritability, poor feeding or tummy pain — and a UTI in a young child should always be assessed by a doctor. People with a urinary catheter are also prone to infection and need particular attention when they become unwell.
Causes and risk factors
Most UTIs occur when bacteria, often from the bowel, enter the urethra and travel up into the urinary tract. Anything that helps bacteria reach the bladder, or that stops the bladder emptying fully, raises the risk. Common risk factors include being female, sexual activity, and the changes of menopause, which alter the tissues of the urinary and genital area. Urinary catheters, an enlarged prostate in men, and anything that blocks or slows urine flow — such as kidney stones — also increase risk. Diabetes, poor fluid intake and the habit of holding urine for long periods each make infection more likely. Recognising personal risk factors helps explain why UTIs recur in some people and guides sensible prevention.
How it is diagnosed
A doctor usually starts with the pattern of symptoms, which alone can point strongly to a UTI. A urine sample may be tested with a dipstick, which can detect signs of infection quickly in the clinic. A urine culture, where the sample is sent to a laboratory to grow and identify the bacteria, confirms the diagnosis and shows which antibiotic will work best — this is especially useful for recurrent, complicated or suspected kidney infections. When infections keep returning, occur in men, or involve the kidneys, a doctor may arrange further tests, such as scans of the urinary tract, to look for an underlying cause like a stone, an obstruction or incomplete bladder emptying.
Treatment
Many simple bladder infections are treated with a short course of antibiotics, and symptoms often start to ease within a day or two. It is important to finish the prescribed course even once you feel better, so the infection is fully cleared and resistance is less likely. Drinking enough fluids helps flush the urinary tract, and simple pain relief can ease the burning and discomfort. Where there is an underlying cause — such as a stone, an enlarged prostate or a catheter problem — treating that is part of getting better and preventing return. Some very mild cases may be managed with fluids and review, only starting antibiotics if symptoms persist, but this is a decision for a doctor to make. A kidney infection generally needs prompt and sometimes longer treatment, and severe cases may require hospital care.
Recurrent UTIs
Recurrent urinary tract infections are common, particularly in women, and repeated episodes deserve more than treating each one in isolation. A doctor will look for treatable contributors — such as incomplete bladder emptying, kidney stones, diabetes, the changes of menopause or, in men, an enlarged prostate — so the cause can be tackled at the source. Alongside general self-care, preventive strategies are tailored to the person; for women who get frequent UTIs after menopause, a doctor may suggest additional measures such as vaginal oestrogen. The aim is to reduce how often infections return rather than simply managing them one at a time.
Prevention and self-care
Sensible habits can lower the risk of UTIs. Stay well hydrated so urine flushes the bladder regularly, and avoid holding urine for long periods. Emptying the bladder after sex, and wiping from front to back after using the toilet, both reduce the chance of bacteria reaching the urethra. Managing constipation and treating underlying conditions — such as controlling diabetes or addressing an obstruction — also helps. These measures are general good practice; anyone with frequent or troublesome infections should ask a doctor which steps are most relevant to them.
When to see a doctor
See a doctor — at a GP or polyclinic — if you have UTI symptoms, and seek care the same day if there is fever, back or side pain, vomiting or blood in the urine, or if the affected person is male, pregnant, a young child, or has a urinary catheter. Recurrent infections and symptoms that are not improving on treatment also warrant review, and a urologist may be involved for complicated or repeated cases. Go to A&E or call 995 for signs of a serious infection or sepsis: new confusion, a very fast heartbeat or breathing, severe illness, feeling faint, or not passing urine. Reliable general information is available on HealthHub, but this article does not replace a personal assessment.
Common questions
Will a UTI go away on its own?
Some mild bladder infections settle, but antibiotics usually clear the infection faster and reduce the risk of it reaching the kidneys, so review is advised.
Why do I keep getting UTIs?
Recurrent UTIs can relate to anatomy, menopause, incomplete bladder emptying, stones or diabetes; investigation helps identify a treatable cause.
When is a UTI serious?
Fever, chills, loin pain or vomiting suggest a kidney infection, which is more serious and needs prompt treatment.
Related guides
- Kidney infection (pyelonephritis)
- Painful urination
- Frequent urination
- Best nephrologists in Singapore
Sources
- HealthHub Singapore — urinary tract infections.
- National Kidney Foundation Singapore — UTI.
- NHS — urinary tract infections.
This article is for general information only and does not replace a consultation with a qualified doctor. If you have severe pain, high fever or cannot pass urine, seek urgent medical care.