Haematuria (Blood in Urine)

What is haematuria?

Blood in your urine is termed haematuria (also referred to as hematuria). Haematuria may be visible to the naked eye or detectable only on examination of the urine sediment by microscopy (non-visible). The source of blood in the urine can be anywhere along the entire course of the urinary tract.

Haematuria can be a sign of a more serious underlying medical condition. If you have it, you should consult your family physician or book an appointment to see a specialist. One in five patients visiting a urologist presents with haematuria.

What are the types of haematuria?

There are two types of haematuria:

Gross haematuria

This occurs when you can visibly see blood in your urine. It is less common and often more noticeable. You should be concerned and seek early medical attention. While gross haematuria may be due to common conditions such as urinary tract infection or urinary stone disease, it may portend cancers arising from the urinary tract.

Microscopic haematuria

In this type, the blood is not visible to the naked eye. It can be detected under a microscope or through a urinalysis test. This is usually identified during routine health check-ups or when investigating other urinary issues. Unlike gross haematuria, microscopic haematuria is usually less concerning and life threatening. Nonetheless, your urologist will perform the necessary investigations to reassure you.

What are the symptoms of haematuria?

You may or may not have any other symptoms associated with haematuria.

If present, these symptoms include:

• Urinary frequency and urgency
• Burning pain when passing urine
• Lower abdominal or back pain
• Fever

When should you see a doctor?

It is advisable to seek early medical attention if you notice any blood in your urine (gross haematuria), especially if it persists, is associated with pain or if you have other concerning symptoms. Seeking timely medical attention enables you to address any potential underlying issues.

How is haematuria prevented?

• Stay hydrated: Drinking sufficient water helps flush the urinary tract and may reduce the risk of infections.
• Practise safe exercise habits: Avoid overexertion and be mindful of your body’s signals. In rare cases, strenuous exercise may result in blood in the urine. If you experience this or any other unusual symptoms, reduce your exercise intensity.
• Maintain a balanced diet: Eating a nutritious diet can help reduce the likelihood of kidney stones, a common cause of haematuria.
• Avoid smoking: Smoking is linked to bladder and kidney cancers, both of which can cause haematuria.
• Monitor medications: Certain medications can increase bleeding risk; consult with a healthcare provider about any potential effects on urinary health.

What causes haematuria?

Possible causes of haematuria include:

Infections

• Urinary tract infections (UTIs): Bacterial infections affecting the urinary system can induce inflammation and cause bleeding.
• Bladder and kidney infections: Infections localised in the bladder or kidney may contribute to urinary bleeding.

Structural problems and physical trauma

• Kidney stones: The passage of kidney stones through the urinary tract can cause pain and bleeding.
• Enlarged prostate: Benign prostatic hyperplasia (BPH) is a common condition in men of old age, in which the prostate becomes enlarged. The enlarged prostate compressing on the urethra opening can lead to bleeding, poor urinary flow, hesistancy and sensation of incomplete emptying
• Physical injuries: Accidents or falls resulting in injuries to the bladder or kidneys may lead to bleeding.
• Strictures: Narrowing of the urinary tract can be a cause of haematuria.
• Underlying health conditions:
• Cancer: Bladder, prostate or kidney and ureteric cancers can manifest as haematuria, especially gross haematuria.
• Disorders of the kidney: Conditions like glomerulonephritis or polycystic kidney disease may cause blood in the urine.
• Blood clotting disorders: Conditions that affect blood clotting increase the risk of bleeding in the urinary system, contributing to haematuria.
• Vascular diseases: Vasculitis or vascular malformations can lead to haematuria.
• Systemic diseases: Disorders like lupus or certain autoimmune conditions impacting multiple organs may also involve the urinary system and manifest as bleeding.

Medications and other indirect causes

• Side effects of medications: Certain drugs, like blood thinners or anti-cancer drugs, may have side effects that contribute to haematuria.
• Indirect contributors: Respiratory or gastrointestinal infections, though not directly related to the urinary tract, may sometimes indirectly cause blood in the urine. Enlarged blood vessels in the lower gut, such as the rectum or anus, though not directly connected to the urinary tract, might result in bleeding from the rectum, which could be confused with haematuria.
• Previous radiation treatment to the pelvis: Radiation therapy to the pelvic region, often used in the treatment of cancers, may damage the bladder lining and result in haematuria.

Miscellaneous causes

• Menstrual factors: Menstrual blood, when inadvertently mixed with a urine sample, can lead to a false appearance of haematuria. It is essential to consider the timing of menstruation when interpreting test results.
• Gynaecological conditions: Certain gynaecological conditions, such as endometriosis or uterine fibroids, can cause bleeding that may be misinterpreted as haematuria if it affects the urinary system. Moreover, following childbirth, changes such as urinary tract injuries, infections or changes in pelvic floor muscles can potentially lead to haematuria.

What are the risk factors for haematuria?

• Age: Older adults, particularly men, are more prone to haematuria due to potential conditions like an enlarged prostate.
• Family history: A family history of kidney disease or other urinary conditions can increase susceptibility to haematuria.
• Smoking: Smoking is linked to a higher risk of bladder and kidney cancers, both of which can cause haematuria.
• Certain medications: Use of blood thinners, anti-inflammatory drugs, or certain antibiotics may increase the likelihood of bleeding in the urinary system.
• Strenuous exercise: High-impact or prolonged exercise, such as long-distance running, can sometimes trigger haematuria.

What are the complications of haematuria?

While it is often a symptom of an underlying condition, haematuria itself can lead to complications if left untreated.

• Urinary tract damage: Persistent haematuria can gradually damage the kidneys and urinary tract over time.
• Blood clots and strictures: Formation of blood clots and strictures in the urinary tract may lead to obstruction and pain.
• Infection risk: Haematuria resulting from urinary tract infections (UTIs) can spread bacteria, potentially causing systemic infections.
• Cancer indication: Haematuria may be an early sign of bladder or kidney cancer. Delayed treatment can lead to disease progression with further complications.
• Quality of life impact: Chronic or recurrent haematuria may significantly reduce quality of life, causing discomfort, anxiety and disruptions to daily activities.

How is haematuria diagnosed?

Your doctor will speak to you more to find out more about your symptoms, and in particular, if you have any risk factors for urinary tract cancers. A clinical examination will be performed during your consultation.

Diagnostic investigations may include:

• Urinalysis. This is a complete examination of the urine.
  • At first, the urine is visually examined for any visible signs of blood, such as discolouration.
  • A dipstick with blood-specific indicators is immersed in the urine to detect the presence of blood, providing a colour change as an indication.
  • A portion of the urine is examined under a microscope to identify red blood cells, providing a more detailed assessment of the quantity and characteristics of blood in the sample. Urine tests may also be used to detect cancer cells.
• Urine culture: Although not typically used for haematuria, a urine culture may be ordered if there is suspicion of an infection causing blood in the urine. It helps identify specific bacteria or other micro-organisms.
• Lab panel: A lab panel can reveal markers associated with kidney function and autoimmune diseases, providing insights into potential causes of haematuria, such as kidney disorders or autoimmune conditions. It may also include kidney function tests.
• Prostate-specific antigen test: In men, this test is used to help identify prostate issues that might cause haematuria.
• MRI and CT scans: Both MRI and high-resolution CT scans offer detailed images and are useful for assessing the kidneys and bladder for abnormalities contributing to haematuria.
• Ultrasound: Ultrasound is often used at the bedside examination to visualise the kidneys and bladder without exposing the patient to X-rays.
• Cystoscopy: Cystoscopy is particularly relevant for haematuria as it allows direct visual inspection of the urethra and bladder. It helps identify sources of bleeding, such as bladder tumours or inflammation.

How is haematuria treated?

• Antibiotics: Prescribed if a urinary tract infection is identified to eliminate the organisms causing the infection.
• Pain management and lithotripsy: Used for treating kidney stones; pain management helps with smaller stones, while larger stones may require lithotripsy or surgical intervention to facilitate removal.
• Surgical intervention: Necessary for structural issues like tumours, strictures or obstructions in the urinary tract.
• Medication adjustment or discontinuation: May be required if haematuria is a side effect of certain medications, done under the guidance of a healthcare professional.
• Management of blood disorders: Essential for cases where blood disorders contribute to haematuria, focusing on treating the underlying blood condition.

References

Barocas, D. A., Boorjian, S. A., Alvarez, R. D., Downs, T. M., Gross, C. P., Hamilton, B. D., Kobashi, K. C., Lipman, R. R., Lotan, Y., Ng, C. K., Nielsen, M. E., Peterson, A. C., Raman, J. D., Smith, -Bindman Rebecca, & Souter, L. H. (2020). Microhaematuria: AUA/SUFU Guideline. Journal of Urology, 204(4), 778–786. https://doi.org/10.1097/JU.0000000000001297

Chen, M.-C., Wang, J.-H., Chen, J.-S., Chang, Y.-C., Jan, R.-H., Yang, S.-H., Chu, S.-Y., Lai, P.-C., Chu, C.-H., Cheng, C.-F., & Chang, Y.-H. (2020). Socio-Demographic Factors Affect the Prevalence of Haematuria and Proteinuria Among School Children in Hualien, Taiwan: A Longitudinal Localization-Based Cohort Study. Frontiers in Pediatrics, 8, 600907. https://doi.org/10.3389/fped.2020.600907

DFTB, T. (2024). Haematuria mimics. Don’t Forget The Bubbles. https://doi.org/10.31440/dftb.62428

Cambridge Urology Partnership. (2022, December 21). Blood in the urine (haematuria). https://www.cambridgeurologypartnership.co.uk/urology-info-for-patients/bladder/blood-in-the-urine-haematuria/

Haematuria - differential diagnosis - investigations. TeachMeSurgery. (2022, July 30). https://teachmesurgery.com/urology/presentations/haematuria/