Blood in Urine — Causes and Why It Needs Checking
Also described as haematuria, red urine, blood while passing urine.
Blood in the urine always needs investigation, even if it happens once and then stops, and even if it is painless. Infections and stones are the commonest causes, but painless bleeding can be the first sign of a bladder or kidney tumour. Iswarya Hospital's Urology department, OMR Chennai, investigates with ultrasound and cystoscopy.
🚨 Get emergency care if you have
- •Painless blood in the urine, particularly over age 50
- •Passing clots, or being unable to pass urine
- •Blood with fever and back pain, suggesting a kidney infection
- •Blood with severe one-sided flank pain coming in waves
What causes blood in urine?
Urinary tract infection
Burning, urgency and frequency, often with cloudy or strong-smelling urine.
Kidney or bladder stones
Severe flank pain in waves, sometimes radiating to the groin, with visible or microscopic blood.
Enlarged prostate
In older men, with a weak stream, hesitancy and getting up at night to pass urine.
Bladder or kidney tumour
Classically painless bleeding. Uncommon, but the reason single episodes are still investigated.
Strenuous exercise
Transient bleeding after intense exertion — a diagnosis made only once other causes are excluded.
How it is investigated
- ✓Urine routine examination and culture
- ✓Ultrasound of the kidneys, ureters and bladder
- ✓CT urogram where stones or a tumour are suspected
- ✓Cystoscopy — a camera examination of the bladder
Not every patient needs every test. The consultation decides which of these apply to you.
Frequently asked questions
I saw blood once and it stopped. Do I still need to see a doctor?▼
Yes. A single episode that resolves does not exclude a serious cause, and bleeding from bladder tumours is characteristically intermittent. One episode of visible blood in the urine is enough reason for an ultrasound and a urology consultation.
Can food or medicines turn urine red?▼
Beetroot, some food colourings and a few medicines can colour the urine. A urine test distinguishes pigment from actual blood within minutes, which is why testing is worthwhile rather than assuming.
This page is general health information, not a diagnosis or a substitute for a consultation. Symptoms overlap between harmless and serious conditions, and only an examination can tell them apart. If you are worried, see a doctor.
Plan your first visit
Not sure which specialist to see? Tell our care team the reason for your visit and we will help you choose.
- Bring previous prescriptions, relevant test reports or scan images, a medication list and photo ID.
- If you plan to use insurance, bring your policy details. OPD, tests and admission benefits depend on your individual plan and approval.
- Your first consultation determines which tests or treatments are needed; not everyone needs every test listed on this page.
Appointments are requests until confirmed. In a medical emergency, call 044 2025 2025 or go to the nearest emergency department.