Causes of Blood in Urine (Haematuria)

The formation of tiny, hard deposits in the kidneys, known as kidney stones, can be a painful and common reason for haematuria. These stones can scrape and damage the urinary tract, leading to blood in the urine as the body tries to eliminate them.

Infections specifically in the bladder or kidneys, rather than the entire urinary tract, can also cause haematuria. These infections are severe causes of inflammation and bleeding within these vital organs.

Blood in the urine results from an injury to the urinary system, whether sustained in an accident or during a medical operation. This may include injuries from catheterisation, urinary tract surgery, or even vigorous physical activities.

Certain medications, especially blood thinners and pain relievers, can lead to increased bleeding and haematuria. Make sure your doctor knows about any medicines you're taking so they can rule them out as possible causes of your symptoms.

Haematuria is a common symptom of benign prostatic hyperplasia (BPH), in which the Prostate grows abnormally big. As the prostate gland enlarges, it may press against the urinary tract, leading to bleeding.

Additionally, renal disease, bladder cancer, and bleeding problems can all cause haematuria. While less common, these conditions require thorough evaluation and appropriate management.

Intense physical activities, particularly those that involve running or high-impact movements, can sometimes lead to haematuria. This is often referred to as "jogger's haematuria." It is usually temporary and resolves with rest.

Menstruation can occasionally lead to blood in their urine, especially when menstrual blood mixes with urine during urination.

Severe dehydration can result in concentrated urine, which may cause irritation and contribute to haematuria. Staying adequately hydrated is essential for urinary tract health.

Blood in the urine presents itself in various forms, each carrying different implications for one's health.

Gross haematuria is the most apparent form of this condition. You can see blood in your urine in gross haematuria, usually with a pink, red, or brownish hue. This is often noticeable to the naked eye and can be distressing for anyone experiencing it. While gross haematuria can be a startling symptom, it does not necessarily indicate an immediate medical emergency.

We have microscopic haematuria on the other end of the spectrum. This type of haematuria is far less conspicuous as you can't see the blood. Instead, it requires a urine sample and a microscope to identify the presence of red blood cells. Microscopic haematuria is often discovered incidentally during routine medical check-ups or when a urine sample is analysed for other reasons.

Regardless of whether haematuria is gross or microscopic, any unexplained or recurrent occurrence of blood in the urine should never be dismissed or underestimated. Blood in the urine may indicate a severe problem with the urinary tract or another organ system. In addition to a thorough history and physical, a doctor may order diagnostic tests, including urinalysis, bloodwork, and x-rays. This approach aims to identify any possible causes of haematuria and guide appropriate treatment or further investigation.

The underlying reason for blood in the urine determines the course of treatment. Some cases may not require specific treatment, especially if the haematuria is due to a benign condition. However, it is essential to see a doctor so that a proper diagnosis can be made as to what is causing the haematuria. Depending on the diagnosis, treatment options may include medication, adjustments to one's routine life, or even surgery.

Dr Alvin Ng is a nephrologist in Singapore with more than 20 years of experience. He specialises in the diagnosis and management of a wide range of kidney conditions and is committed to providing comprehensive, personalised and evidence-based care for patients with kidney disease.

Prior to private practice, Dr Ng served as a consultant nephrologist at Changi General Hospital, where he was Director of the Peritoneal Dialysis Service and a member of the MOH Peritoneal Dialysis Workgroup. He has also held leadership roles within the Singapore Society of Nephrology and has been actively involved in the education of medical students, junior doctors and specialist trainees. His contributions to patient care, medical education and professional service have been recognised through multiple awards.