Hematuria (Blood in Urine)
Conditions · Hematuria (blood in urine)
Blood in the urine (hematuria): what it means, the three-glass test, every cause from cystitis to cancer, and what to do today
Red, pink or cola-coloured urine, or red cells found on a routine test you never noticed, is hematuria. It is a sign, not a disease, and in most people the cause is an infection, a stone or an inflamed prostate. But it is also the way bladder and kidney cancers announce themselves, and painless blood in the urine in a smoker or anyone over 40 must never be put down to “a bit of infection” without investigation. This page explains how to read the colour and the timing, what the three-glass test tells us, the causes by age and sex, the tests that find the source, and how each cause is treated.
Hematuria at a glance
What is hematuria?
Hematuria is the presence of red blood cells in the urine. When there is enough to colour the urine, pink, red, brown or like cola, it is called macroscopic (visible, gross) hematuria; as little as a millilitre of blood in a bladderful of urine is enough. When the urine looks normal and the cells are found only under the microscope or on a dipstick, usually three or more red cells per high-power field on two samples, it is microscopic hematuria, and it is found in a few percent of adults on routine testing. Both kinds are symptoms of something else, and the something else ranges from the trivial to the serious. The distinction matters less than people think: a bladder tumour can present with either, and microscopic hematuria needs the same thought as visible blood, if less urgency.
Reading the sign: colour, clots, pain and timing
Painful or painless
Pain with the blood, burning on urination, frequency and urgency, points to infection: cystitis in women, prostatitis or urethritis in men. Colicky pain in the loin radiating to the groin with blood is a stone on its way down the ureter. Painless, visible blood, especially in a smoker or anyone over 40, is a tumour of the bladder or kidney until proven otherwise.
Colour and clots
Bright red blood with clots comes from the bladder, prostate or urethra; clots shaped like worms have passed down a ureter from a kidney. Smoky, brown or cola-coloured urine without clots suggests bleeding from the kidney itself, from the filtering units (glomeruli), and goes with kidney disease rather than urology.
Microscopic or visible
Visible blood is investigated in everyone. Microscopic blood is investigated in anyone over 35 to 40, in smokers, in anyone with urinary symptoms, and when it persists on repeat testing; in young people with a single finding and a normal repeat, it is usually benign.
Blood in semen as well
When the semen is also brown or red, the source is almost always the prostate and seminal vesicles; see our page on blood in semen.
The three-glass test (Guyon’s test)
A simple, old and still useful bedside test: the patient urinates into three glasses in one go, the first few millilitres into the first, the bulk into the second, the last drops into the third, and the colour of each is compared. It tells us at what point in the stream the blood appears, and therefore roughly where it comes from.
- Initial hematuria (only the first glass is red): the blood is washed out at the start of the stream, so it comes from the urethra or the prostatic urethra: urethritis, a stricture, a polyp or a lesion of the urethra, or an inflamed, congested prostate.
- Terminal hematuria (only the last glass is red): the blood appears as the bladder squeezes its last drops, so it comes from the bladder neck or the prostate: prostatitis, prostatic enlargement, a tumour at the bladder neck, or inflammation of the trigone.
- Total hematuria (all three glasses are red): the blood is mixed through the urine, so it comes from the bladder, the ureters or the kidneys: cystitis, bladder tumours, stones, kidney tumours or kidney disease.
The test does not replace imaging and cystoscopy, but it points the investigation in the right direction from the first visit. In men, initial and terminal hematuria very often lead us to the prostate.
Other things the history tells us
Age and sex (cystitis dominates in young women, prostatitis in young men, enlarged prostate and tumours over 50); smoking and occupational exposure to dyes and chemicals, the main risk factors for bladder cancer; recent strenuous exercise, a long run or cycle, which can cause a day of harmless hematuria; a recent sore throat or infection, which precedes some kidney diseases; anticoagulants and antiplatelet drugs, which make any bleeding visible and must never be blamed on their own; family history of kidney disease or stones; sickle-cell disease and trait; endocarditis and other general illnesses; diabetes and hypertension, which damage the kidneys; and, for women, whether the sample could have been contaminated by menstrual blood.
The causes of blood in the urine
Any condition of the urinary tract can cause hematuria, and causes vary with age. It is worth remembering that general diseases and medicines can coexist with a urological cause: the man on aspirin with blood in his urine may also have a bladder tumour, and the aspirin only made it visible.
Infections and inflammation
The commonest cause at every age. In women, acute and chronic cystitis, with burning, frequency and urgency; in men, chronic prostatitis, which bleeds from the congested prostatic urethra at the start or end of the stream, and urethritis from sexually transmitted organisms. Kidney infection (pyelonephritis) adds fever and loin pain. Tuberculosis and schistosomiasis of the bladder are rare in Greece but still seen.
Stones
Kidney stones passing down the ureter scratch its lining and cause blood with colicky pain, often with nausea; bladder stones cause blood at the end of urination and a stream that stops and starts. Stones are the second commonest cause in adults under 50.
Enlarged prostate (BPH)
The enlarged gland is covered by fragile, engorged veins that bleed easily, especially with straining; blood at the start or end of the stream in a man over 50 with a weak stream and night-time urination is typical, but a tumour must still be excluded. See our page on BPH.
Tumours of the urinary tract
Bladder cancer presents with painless visible hematuria in the great majority of cases, often intermittent, so that the patient is falsely reassured when it stops. Kidney cancer causes blood, loin pain and sometimes a mass. Cancers of the ureter and urethra are rarer. Prostate cancer causes hematuria less often, usually when advanced. Every episode of visible, painless hematuria is treated as a possible tumour until the investigation says otherwise.
Kidney (glomerular) disease
Inflammation of the kidney’s filters, IgA nephropathy, post-infectious and other glomerulonephritis, thin basement membrane disease, Alport syndrome, causes brown, smoky urine with protein and abnormal red cells, often after an infection, and is managed with a nephrologist. Diabetes and hypertension damage the kidneys slowly and can do the same.
Everything else
Injury to the kidney or bladder; strenuous exercise; catheters and procedures; radiotherapy; drugs such as cyclophosphamide; bleeding disorders and anticoagulants (warfarin, the newer anticoagulants, aspirin and clopidogrel); sickle-cell disease and trait; endocarditis and vasculitis; polycystic kidneys; and endometriosis of the bladder, which bleeds with the period.
See a urologist within days, not weeks, for any visible blood in the urine without pain, especially if you are over 40, smoke or have ever smoked, or have worked with dyes, rubber or chemicals; for blood with clots; for blood with fever, shaking or loin pain; and for blood that keeps returning even if it stops in between. Go to an emergency department the same day if you cannot pass urine, if you are passing large clots, if the bleeding is heavy and continuous, or if you have had a significant injury. Never accept “it is just a bit of infection” without a urine culture that proves it and a check that the blood has gone after treatment.
How the source is found
In the men we see, this sequence very often ends at the prostate: a chronically inflamed gland on transrectal ultrasound, white cells and bacteria in the prostatic fluid, and blood at the start or end of the stream that stops once the prostatitis is treated. But the bladder and kidneys are checked first, every time, because the cost of missing a tumour is far higher than the cost of a scan.
Treatment of hematuria
By cause
Infections are treated on the basis of the culture, and for a chronically inflamed prostate or bladder that means treating the gland, not a week of tablets. Stones are passed, dissolved or broken up. An enlarged prostate that bleeds is treated with medicines or surgery. Tumours are removed, through the urethra for most bladder tumours, and followed up for life. Kidney disease is managed with the nephrologist. Anticoagulant doses are reviewed with the doctor who prescribed them, once a urological cause has been excluded.
Heavy bleeding with clots
Clots can block the urethra and cause painful retention. This needs a catheter and bladder washouts (lavage) in hospital, sometimes continuous irrigation, until the bleeding settles and the cause can be treated; drinking plenty helps only with light bleeding.
After treatment
The urine is checked after treatment to confirm the blood has gone; blood that persists after an infection has been “cured” means the infection was not the cause. Men over 40 and anyone with risk factors are followed with urine tests and, where a tumour was found, with scheduled cystoscopies.
Red urine that is not blood
Beetroot, blackberries, rhubarb and food dyes; rifampicin, phenazopyridine, nitrofurantoin, some laxatives and chemotherapy drugs; myoglobin after muscle injury or extreme exercise; haemoglobin after a haemolytic reaction; porphyrins in porphyria; and urine that has been concentrated by dehydration. A dipstick and a microscope distinguish all of these from real hematuria in minutes, which is why red urine is tested rather than guessed at.
Seen blood in your urine?
Bring the details: when, with what pain, how often, and what you take. In one visit we test and culture the urine, examine you, scan the kidneys, bladder and prostate, and tell you honestly where the blood is coming from and what needs doing next.
Blood in urine: frequently asked questions
What does blood in the urine mean?
That something in the urinary tract, from the kidneys to the urethra, is bleeding. The commonest causes are infection (cystitis in women, prostatitis in men), stones and an enlarged prostate; the most important are tumours of the bladder and kidney, which usually bleed without pain. The cause is found by testing, not by guessing.
Is painless blood in the urine serious?
It can be. Painless, visible hematuria, particularly over 40 or in a smoker, is the classic presentation of bladder cancer and needs cystoscopy and imaging within days. Most such patients turn out not to have cancer, but the only way to know is to look.
What is the three-glass test for hematuria?
Urinating into three glasses in succession and comparing their colour. Blood only in the first glass comes from the urethra or prostatic urethra; only in the last from the bladder neck or prostate; in all three from the bladder, ureters or kidneys. It directs the investigation from the first visit.
Can a urinary tract infection cause blood in the urine?
Yes, and it is the commonest cause, with burning, frequency and urgency. The infection should be proved by culture and the urine re-checked after treatment: blood that persists once the infection has cleared has another cause.
What causes blood in the urine in men?
In young men, prostatitis and urethritis most often, then stones; in older men, an enlarged prostate, bladder tumours and stones. Blood at the start or end of the stream points to the prostate; the bladder and kidneys are still checked.
What causes blood in the urine in women?
Cystitis above all, then stones; contamination by menstrual blood must be excluded; bladder tumours are less common than in men but occur, particularly in smokers. Recurrent “cystitis” with blood that keeps coming back needs a culture every time and, if the cultures are negative, a cystoscopy.
Does microscopic hematuria need investigating?
If it persists on a repeat sample, yes, especially over 35 to 40, in smokers, or with any urinary symptom: urine tests, ultrasound and, depending on risk, cystoscopy. A single finding in a young person with a normal repeat is usually benign.
Can exercise cause blood in the urine?
Yes; a long run, cycle or intense training can cause a day of visible or microscopic hematuria from the bladder or from muscle breakdown. It should clear within 48 to 72 hours of rest; if it does not, or it recurs without exercise, it is investigated like any other hematuria.
