Right, so you’ve noticed blood in your urine. I won’t sugarcoat it—that’s properly alarming. The medical term is haematuria, and whilst it’s one of those symptoms that sends most people into a bit of a panic (understandably), the causes range from ‘absolutely nothing to worry about’ to ‘you need to see someone rather quickly’. Let’s talk through what might be going on.
When It’s Actually More Common Than You’d Think
Here’s something that might surprise you: blood in urine is far more common than most people realise. According to NHS guidance, around 1 in 5 people will experience haematuria at some point. Sometimes you can see it—that’s called gross or visible haematuria. Other times it’s only picked up on a urine test at your GP surgery, which is termed microscopic haematuria.
The tricky bit? The amount of blood doesn’t correlate with how serious the underlying cause is. You might have just a trace that makes your urine slightly pink, or it could be quite dramatically red. Neither tells you much about what’s actually happening.
I think it’s worth mentioning that certain foods can play tricks on you too. Beetroot, anyone? I’ve had three separate friends convinced they were dying, only to remember the rather substantial amount of beetroot they’d eaten the day before. Blackberries and rhubarb can do similar things. Not technically haematuria, but it’ll certainly give you a fright.
The Usual Suspects: Infections and Stones
If we’re talking about the most likely causes—particularly in younger adults—urinary tract infections top the list. UTIs cause inflammation in the bladder or kidneys, and that irritated tissue can bleed. You’ll usually have other symptoms though: burning when you pee, needing to go constantly, that urgent feeling, perhaps some lower tummy pain.
Kidney stones are another major culprit. These little crystallised minerals can scrape the lining of your urinary tract as they move through, causing bleeding. The pain from kidney stones is often described as one of the worst things people have experienced—sharp, coming in waves, typically in your back or side. A 2022 study published in the Journal of Urology found that about 10% of people will develop a kidney stone at some point in their lives, with rates climbing in recent years (possibly linked to dietary changes and increased rates of obesity).
Then there’s exercise-induced haematuria. Yes, really. Long-distance runners sometimes develop temporary blood in their urine after particularly intense exercise. The exact mechanism isn’t fully understood, but it’s thought to involve repeated jarring of the bladder, dehydration, or reduced blood flow to the kidneys during intense activity. It typically resolves on its own.
Things That Need Checking Sooner Rather Than Later
Now, let’s talk about the causes that make doctors sit up and take notice. Bladder cancer is obviously the concern that crosses most people’s minds, and haematuria is indeed its most common presenting symptom. But—and this is important—most cases of haematuria aren’t cancer.
According to NHS statistics, bladder cancer affects around 10,000 people in the UK each year, with smoking being the single biggest risk factor. It’s more common in older adults, particularly men over 60. If you’re experiencing painless visible haematuria and you’re in that age bracket, your GP will want to investigate fairly quickly.
Prostate problems in men can cause haematuria too—both benign enlargement (which affects most men as they age) and prostate cancer. The prostate sits just below the bladder, so when it enlarges, it can cause irritation and bleeding.
Kidney disease is another possibility. This might be inflammation of the kidney’s filtering units (called glomerulonephritis), which can happen after certain infections or as part of autoimmune conditions. Sometimes there’s a family history of kidney problems, which is a helpful clue.
What About Medications and Medical Procedures?
Certain medications can cause haematuria. Blood thinners like warfarin or the newer anticoagulants can make you more prone to bleeding anywhere, including your urinary tract. Cyclophosphamide, a chemotherapy drug, is known for causing bladder inflammation and bleeding.
If you’ve recently had a procedure involving your bladder or kidneys—perhaps a catheter, a cystoscopy, or kidney biopsy—some blood in your urine afterwards isn’t unusual. It should settle down fairly quickly though.
Vigorous sexual activity can occasionally cause temporary haematuria, particularly in women. It’s not something most people bring up with their GP (British reserve and all that), but it’s generally harmless and resolves on its own.
There’s also inherited conditions like sickle cell disease or bleeding disorders that can manifest as haematuria, though these usually come with a known diagnosis and other symptoms.
Look, the bottom line is this: any blood in your urine warrants a conversation with your GP, even if you think you know what caused it. They’ll likely do a urine test, possibly some blood tests, and depending on your age and risk factors, might refer you for further investigation. It’s probably nothing serious, but it’s not something to ignore or hope resolves on its own. Most causes are entirely treatable, especially when caught early.
