Blood in Urine: What It Could Indicate

Finding blood in your urine is alarming. Most people's first instinct is to either panic or convince themselves it was a one-off and move on. Neither response is quite right. Blood in urine, medically called hematuria, warrants attention and evaluation, but it does not automatically mean something serious. What it does mean, without exception, is that it should not be ignored.

The range of conditions that can cause hematuria is wide, from something as straightforward as a urinary tract infection to something that requires urgent investigation, like a tumour. The only way to tell the difference is through proper medical assessment.

Two types: visible and invisible

Not all hematuria looks the same. When urine appears red or pink, it is called gross or visible hematuria. When blood is present but the urine looks normal to the naked eye, it is called microscopic hematuria, detectable only through a urine test or microscope.

An important point many patients miss: the amount of visible blood says very little about the seriousness of the cause. A dramatic red discolouration can sometimes come from a minor source, while microscopic hematuria found incidentally on a routine test can occasionally signal something that needs urgent follow-up. The goal of any work-up is to make sure that urinary tract cancers are not missed; when found early, outcomes are significantly better.

It is also worth noting that certain foods, notably beetroot, and some medications can temporarily turn urine pink or red without any blood being present. A urine test will confirm whether actual red blood cells are present.

What causes blood in urine?

The causes range from benign to serious, and a doctor's evaluation is needed to determine which applies in any individual case.

Urinary tract infections

UTIs are one of the most common causes of haematuria, especially in women. The infection causes bleeding by irritating and inflaming the lining of the bladder or urethra. Accompanying symptoms usually include burning with urine, increased frequency, and sometimes fever. In women, haematuria is commonly attributed to a urinary tract infection and treated with antibiotics. If the blood in urine continues after treatment or recurs , additional investigation is crucial.

Kidney stones

Urinary stone disease, which includes kidney stones, ureteral stones, and bladder stones, is a serious and common cause of hematuria. As a stone moves through the urinary tract, it can scrape and damage the delicate lining of the ureters or bladder, causing bleeding. This type of hematuria is often accompanied by significant pain, typically a sharp, cramping sensation in the back, side or groin.

Enlarged prostate

In men, an enlarged prostate, whether due to benign prostatic hyperplasia or prostate cancer, can cause hematuria. Benign prostatic hyperplasia causes the prostate to grow, which can compress the urethra and produce bleeding. Any hematuria in men above the age of 50 should prompt a prostate assessment as part of the evaluation.

Kidney disease

Damage to the tiny filtering units of the kidneys, the glomeruli, can allow red blood cells to leak into the urine. Conditions such as glomerulonephritis, IgA nephropathy, and polycystic kidney disease can all present with hematuria, sometimes without any pain or other obvious symptoms.

Cancer

Hematuria can be the first sign of prostate cancer, kidney cancer, or bladder cancer. This is one of the most clinically significant causes and it is why hematuria should never be dismissed, particularly in older patients. In older adults and smokers, visible hematuria is associated with a 10 to 20% risk of underlying urothelial carcinoma. Bladder cancer in particular tends to cause painless hematuria, blood without burning, without discomfort, and without any other signal that something is wrong. That absence of pain is precisely why it gets missed.

Other causes

• Strenuous physical exercise can occasionally cause transient hematuria, particularly in runners
• Certain medications including blood thinners and some antibiotics can produce blood in urine
• Inherited conditions such as sickle cell disease and lupus can affect the kidneys and cause hematuria
• Trauma or physical injury to the kidneys or urinary tract

How it is diagnosed?

A urine test is the starting point. From there, depending on findings, a doctor may order:

• Urine culture used to identify bacterial infection
• Blood tests to examine kidney function and look for indicators such as PSA in males.
• Ultrasound or CT scan to examine the kidneys, ureters and bladder for stones, cysts or masses
• Cystoscopy – A narrow tube with a tiny camera is put into the bladder to look directly for sources of bleeding, tumours or other abnormalities
• Urine cytology test to look for cancer cells in the urine under a microscope. 

When to seek care urgently

While all episodes of hematuria warrant medical evaluation, some situations require prompt attention:

• Visible blood in urine appearing for the first time, even if painless
• Blood accompanied by large clots, which can indicate significant bleeding
• Hematuria with fever, which may signal an infected, obstructed kidney
• Blood in urine in anyone above 40 with a history of smoking, a high-risk group for bladder cancer
• Hematuria that clears and then returns, intermittent bleeding should never be assumed to have resolved

Takeaways

Blood in urine, whether visible or detected on a urine test, should always be medically evaluated. Hematuria causes range from common and treatable conditions like UTIs and kidney stones to serious ones like kidney or bladder cancer. The amount of blood visible does not indicate the severity of the underlying cause. 

Painless hematuria, in particular, is a known early warning sign of bladder cancer and should never be dismissed. A urinalysis, urine culture, imaging, and where indicated, cystoscopy, form the standard path to diagnosis. Early investigation consistently leads to better outcomes.