Blood in the Urine: Haematuria Causes and Treatment

Blood in urine, medically termed haematuria, signals that somewhere along your urinary tract—kidneys, ureters, bladder, or urethra—blood cells are entering the urine stream. The colour can range from pink tinges to deep red or cola-coloured urine. This depends on where the bleeding originates and how much blood is present. Haematuria divides into two categories: gross haematuria (visible to the naked eye), and microscopic haematuria (detectable only through laboratory testing). Both warrant medical attention because the urinary tract doesn’t normally release blood cells into urine.

Visible vs Microscopic Haematuria

Gross haematuria produces urine colour changes that patients notice themselves, ranging from light pink to bright red to brownish, similar to tea or cola. The timing of blood appearance during urination may sometimes offer initial clues to your urologist, for example, whether blood appears at the start, throughout, or at the end of the stream.

However, timing alone is not a reliable indicator of the underlying cause, and a thorough investigation is always required regardless of the pattern.

Microscopic haematuria produces no visible changes. It appears on routine urinalysis when laboratory examination reveals red blood cells under microscopy. Patients frequently discover microscopic haematuria incidentally during health screenings or pre-employment examinations without any accompanying symptoms.

Red Blood Cell Morphology

Laboratory analysis can distinguish between glomerular (from the kidney’s filtering units) and non-glomerular bleeding by examining red blood cell shapes.

Dysmorphic red blood cells, particularly a subtype called acanthocytes, which have a distinctive ring shape with protruding blebs, suggest the blood has passed through the kidney’s filtering structures and may point toward glomerular kidney disease.

Uniformly shaped red blood cells typically suggest bleeding from the lower urinary tract. However, RBC morphology is one piece of the diagnostic picture; your urologist or nephrologist will interpret these findings alongside other test results before drawing conclusions.

Common Haematuria Causes

Urinary Tract Infections

Bacterial infections of the bladder (cystitis) or kidneys (pyelonephritis) commonly produce blood in urine. The infection irritates and inflames the urinary tract lining. This causes small amounts of bleeding. Accompanying symptoms typically include:

• Burning during urination
• Frequency
• Urgency
• Sometimes fever with kidney infections

Urine culture identifies the specific bacteria. This helps guide antibiotic selection.

Kidney and Bladder Stones

Stones form when minerals in urine crystallise and aggregate. As stones move through the urinary tract, they scratch and irritate the delicate lining. This produces bleeding. Kidney stones often cause severe flank pain radiating toward the groin—renal colic—alongside haematuria. Bladder stones may cause intermittent blood in urine with lower abdominal discomfort and urinary stream interruption.

Benign Prostatic Hyperplasia

In men, prostate gland enlargement can cause haematuria. In men, an enlarged prostate (BPH) may lead to haematuria due to increased blood vessels associated with the enlarged tissue. This bleeding often occurs alongside other lower urinary tract symptoms such as weak stream, hesitancy, and incomplete bladder emptying.

Vigorous Exercise

Strenuous physical activity occasionally triggers haematuria, particularly in long-distance runners. Exercise-induced haematuria can occur through bladder trauma from repeated impact or dehydration effects. It typically resolves with rest.

Medications

Blood-thinning medications (anticoagulants and antiplatelet agents) increase bleeding tendency throughout the body, including the urinary tract. However, haematuria in patients on blood thinners still requires investigation. The medication may have unmasked an underlying lesion that would otherwise bleed minimally.

Bladder and Kidney Conditions

Various conditions affecting the bladder lining and kidney tissue produce haematuria. These range from inflammatory conditions to growths requiring treatment. Painless gross haematuria warrants thorough evaluation to identify or exclude significant pathology.

The Diagnostic Process

Initial Assessment

Evaluation begins with detailed history-taking. This includes:

• Timing of blood appearance
• Associated symptoms
• Recent activities
• Medication use
• Personal or family medical history

Physical examination includes abdominal palpation, flank percussion, and in men, prostate examination.

Urine Tests

Urinalysis provides initial information. It confirms blood presence, checks for infection markers (white blood cells, bacteria), and identifies protein (suggesting kidney involvement). Urine cytology may be used in selected cases — such as for patients with persistent haematuria after a negative initial workup, particularly those with irritative voiding symptoms or risk factors for carcinoma in situ. It is not recommended as a routine first-line test for all patients with haematuria. Your urologist will determine whether cytology is appropriate based on your individual risk profile.

Blood Tests

In men, PSA (prostate-specific antigen) testing may also be ordered to screen for prostate-related conditions.

Imaging Studies

Ultrasound offers radiation-free initial imaging. It visualises kidney structure, stones, and bladder abnormalities. It can detect hydronephrosis (kidney swelling from obstruction) and large masses, but has limitations for smaller lesions.

CT Urogram provides detailed cross-sectional imaging of the entire urinary tract. CT urogram provides detailed cross-sectional imaging of the entire urinary tract using a multi-phase protocol: an initial unenhanced scan, followed by contrast-enhanced nephrographic and excretory phase images. This sequence allows detection of stones, renal masses, urothelial tumours, and structural abnormalities throughout the urinary system.

MRI Urogram serves as an alternative when CT is contraindicated or less suitable, including patients with contrast allergies, significantly reduced kidney function, pregnancy, or those requiring repeat imaging where minimising radiation exposure is a priority. Your urologist or radiologist will advise on the most appropriate imaging modality for your situation.

Cystoscopy

This procedure involves passing a thin camera through the urethra into the bladder. This allows direct visualisation of the bladder lining and urethra. Cystoscopy can identify lesions that imaging may miss and permits biopsy of suspicious areas. Modern flexible cystoscopes allow in-clinic procedures with local anaesthetic. Patients may experience mild discomfort during the procedure.

Risk Factors Warranting Thorough Evaluation

Certain factors increase the importance of a comprehensive investigation:

• Visible haematuria in adults
• Smoking history (current or past)
• Occupational exposure to chemicals or dyes
• Previous pelvic radiation
• Chronic urinary tract infections
• History of bladder conditions
• Family history of urinary tract malignancy

What Our Urologist Says

Patients sometimes delay seeking evaluation because bleeding episodes resolve spontaneously.

Intermittent haematuria—appearing, disappearing, then recurring—warrants medical evaluation. Even when bleeding resolves on its own, the underlying cause cannot be reliably determined from the pattern alone. Your urologist will assess your individual risk factors to determine the appropriate level of investigation, as not all cases require the same workup.

Steps to Prepare for Your Evaluation

Document your observations before the appointment. Note when you first noticed blood, how often it occurs, the urine colour, and any accompanying symptoms (such as pain, fever, or burning during urination).

List all medications, including over-the-counter drugs, supplements, and blood thinners. Bring the actual bottles if possible so the doctor sees the exact doses.

Prepare for urine collection by following your clinic’s instructions before your appointment. You will likely be asked to provide a clean-catch midstream urine sample. Avoid excessive fluid intake beforehand, as this can dilute the sample and affect test accuracy.

Gather previous records if you’ve had urological investigations elsewhere. This includes imaging reports, laboratory results, and procedure notes.

Note relevant family history including any relatives with kidney disease, bladder conditions, or kidney stones.

When to Seek Professional Help

• Visible blood in urine (pink, red, or brown discolouration)
• Blood clots in urine
• Haematuria with pain during urination or flank pain
• Microscopic haematuria detected on routine testing
• Recurrent urinary tract infections with blood in urine
• Haematuria with unexplained weight loss
• New haematuria while taking blood-thinning medications

Commonly Asked Questions

Can dehydration cause blood in urine?

Mild dehydration can cause urine to appear darker but does not directly cause blood in the urine. However, severe or chronic dehydration can stress the kidneys and may indirectly contribute to haematuria by increasing the risk of kidney stones or urinary tract infections — both of which are known causes of bleeding. It is also worth noting that significant dehydration can affect the accuracy of urine dipstick tests. True blood in urine requires investigation regardless of hydration status.

Should I stop my blood thinners if I see blood in urine?

Do not stop prescribed blood thinners without consulting your doctor. While these medications increase bleeding tendency, haematuria in anticoagulated patients still requires evaluation to identify the bleeding source. Your doctor can advise on medication management tailored to your specific situation.

How long does the investigation take?

Initial urine tests and blood work provide results within days. Imaging studies are typically completed within a reasonable timeframe. Cystoscopy, if needed, can often be performed as an outpatient procedure. Complete evaluation may span several weeks depending on findings.

Can haematuria resolve without treatment?

Some causes, like minor infections or exercise-induced haematuria, resolve with simple measures. However, the underlying cause must be identified first. Self-resolving bleeding doesn’t eliminate the need for evaluation.

Is microscopic haematuria serious?

Microscopic haematuria has the same range of potential causes as visible haematuria. While often resulting from benign causes, it can occasionally indicate significant pathology. Current guidelines use a risk-stratified approach, based on factors such as age, smoking history, and degree of haematuria, to guide the level of investigation recommended. Even a single confirmed episode of microscopic haematuria warrants discussion with a urologist to determine the appropriate next steps for your individual situation.

Conclusion

Haematuria requires systematic evaluation to identify the underlying cause. A comprehensive investigation typically includes urine tests, imaging studies, and, when indicated, cystoscopy. Do not dismiss bleeding that resolves spontaneously — the appropriate level of investigation will be guided by your individual risk factors, which your urologist will assess during your consultation.

If you’re experiencing visible blood in urine, blood clots, or have microscopic haematuria detected on routine testing, consult a urologist for a comprehensive evaluation and diagnosis.