Blood in Urine (Hematuria) in Men: Causes, When It's Serious, and What Tests You Need

Blood in urine — called hematuria — is not always a sign of something dangerous, but it should never be ignored. In some men it comes from a harmless cause like a urinary infection or vigorous exercise. In others, it is the first and only warning sign of a kidney stone, a bladder tumour, or a kidney condition. The only way to know which one applies to you is a proper urine test and, in most cases, an imaging scan. If you have seen blood in your urine even once, book a urology consultation rather than waiting for it to happen again. This guide explains what causes blood in urine, how to tell visible from hidden blood, which tests a urologist actually orders, and the warning signs that mean you should get checked immediately rather than wait.

Hematuria falls into two categories, and the difference matters for how urgently you need to act.

Gross hematuria — urine that is visibly pink, red, or cola-coloured. Even a small amount of blood can noticeably change urine colour, so the appearance does not tell you how serious the cause is.

Microscopic hematuria — blood that is invisible to the eye and only shows up on a urine test. This is often picked up incidentally during a routine health check-up or a test done for another reason.

Both types need to be evaluated. A common myth is that if the urine looks completely normal, there is nothing to worry about — but microscopic hematuria can be caused by the same conditions as visible blood, including early-stage bladder tumours.

Urinary tract infection (UTI): Infection irritates the lining of the bladder and urethra, which can cause blood along with burning urination, urgency, and lower abdominal discomfort. This is one of the most common and most treatable causes, especially when blood appears together with pain or fever.

Kidney or ureteric stones: A stone moving through the urinary tract can scratch the lining and cause blood, usually along with sudden, severe flank pain that comes in waves. A CT scan is usually needed to locate the stone precisely.

Enlarged prostate (BPH): In older men, an enlarged prostate can cause congested blood vessels around the bladder neck to bleed, particularly during straining or after vigorous activity. This is often accompanied by a weak stream, frequent urination, or getting up multiple times at night.

Bladder or kidney tumours: This is the cause every urologist screens for first in painless hematuria, especially in men over 50, smokers, or those with a history of chemical exposure. Painless visible blood in urine is one of the most reliable early warning signs of bladder cancer, and it can appear on and off — disappearing for weeks and then returning — which often makes people delay a check-up. It should never be dismissed just because it resolved on its own.

Trauma or vigorous exercise: A direct blow to the lower abdomen, pelvis, or back, or intense long-distance running, can cause temporary 'exercise hematuria' that clears on its own. This is a diagnosis of exclusion — it should only be assumed after other causes have been ruled out.

Blood thinners and certain medications: Drugs like aspirin, warfarin, or newer anticoagulants don't usually cause bleeding on their own, but they can unmask an underlying problem — such as a stone or tumour — that was bleeding minimally already. If you're on blood thinners and notice blood in urine, it still needs evaluation; don't assume the medication is the full explanation.

Kidney disease: Conditions affecting the kidney's filtering units can cause microscopic or, less commonly, visible blood, often with associated protein in the urine.

Get checked the same day, or go to an emergency department, if blood in urine comes with any of the following:

Inability to pass urine, or passing only clots.

Severe flank or abdominal pain.

Fever with chills.

Significant blood loss with dizziness or weakness.

Blood in urine after a recent injury to the abdomen or back.

Even without these red flags, any visible blood in urine — even a single episode — warrants a urology visit within the next few days.

A structured work-up is what separates a harmless cause from one that needs early treatment. Depending on your history, a urologist typically orders:

Urine routine and microscopy (urine R/M): confirms blood is actually present and checks for infection or protein.

Urine culture: if infection is suspected, to identify the organism and correct antibiotic.

Urine cytology: looks for abnormal cells shed from the bladder lining, used mainly when tumour is a concern.

Ultrasound of the kidney, ureter, and bladder (KUB): a first-line scan to look for stones, masses, or structural issues.

CT urogram: a more detailed scan, often the gold standard for evaluating hematuria in men over 35 or with risk factors.

Cystoscopy: a direct look inside the bladder with a thin camera, usually reserved for higher-risk cases or when other tests are inconclusive.

Not everyone needs every test — the urologist decides the combination based on age, risk factors, and how the blood presented.

Visible blood, no pain, first time — see a doctor within a few days.

Visible blood with severe pain or fever — same day / emergency.

Microscopic blood found on a routine test — within 2–4 weeks.

Blood in urine in a smoker or age 50+ — do not delay, book promptly.

Don't wait for it to happen again. Book a consultation with Dr. Vikram for a proper evaluation and the right tests to find the exact cause.