Hematuria (Blood in the Urine)

Hematuria (Blood in the Urine)

Hematuria is blood in the urine. It is either gross hematuria, when the blood is visible in urine or microscopic hematuria—when the blood in the urine is invisible and only seen under a microscope.

At times the urine may just appear high-colored, or dark colored.

Hematuria – color of the urine

Anatomy of the urinary tract

What is the urinary tract?

The urinary tract is the urinary drainage system for removing wastes and extra fluid. The urinary tract includes

  • 2 kidneys
  • 2 ureters
  • bladder
  • urethra
  • prostate in males

The urine flows from the kidneys to the bladder through tubes called ureters. The bladder stores urine until releasing it through urination. When the bladder empties, urine flows out of the body through a tube called the urethra at the bottom of the bladder. The prostate encloses the initial part of the urethra when it emerges from the bladder.

Anatomy of the urinary tract

What are the causes of hematuria (blood in the urine)?

Blood in the urine originates from any disease from anywhere along the whole of the urinary tract.

The causes of blood in the urine is anywhere along the urinary tract from the kidneys, ureter, bladder, prostate and even testicles. At times it may be beyond the kidneys, known as pre-renal causes.

Causes of blood in the urine include

Serious causes:

  • bladder, prostate or kidney cancer
  • inflammation or infection of the kidney, urethra, bladder, or prostate
  • Urinary stones in kidney, ureter, bladder or urethra
  • Trauma (injury) – kidney, bladder, urethral injury
  • blood-clotting disorders, such as hemophilia
  • sickle cell disease
  • polycystic kidney disease

Other less serious causes:

  • BPH (“enlarged prostate”)
  • vigorous exercise
  • viral illness, such as hepatitis
  • sexual activity
  • menstruation
  • endometriosis
  • medications – certain medications may cause blood in the urine to be more visible, but one needs to determine the underlying cause of the disease


Causes of hematuria. Pic from Business Mirror; https://businessmirror.com.ph/2019/08/22/hematuria/

Risk factors

Those who are at risk of blood in the urine may:

  • have history of cancer of the kidney, bladder or prostate
  • have an enlarged prostate
  • have urinary stones
  • take certain medications, including blood thinners, aspirin and other pain relievers, and antibiotics
  • do strenuous exercise, such as long-distance running
  • have a bacterial or viral infection, such as streptococcus or hepatitis
  • have a family history of kidney disease
  • have a disease or condition that affects one or more organs


Confirmatory diagnosis is by urine examination.

Sometimes the blood in urine may be not be visible (known as microscopic hematuria), and only detected from the urine microscopy test. This invisible urine is still a very significant finding and you need to see the doctor for a proper assessment.

All patients once evaluated by a risk-based approach for hematuria need at least a cystoscopy and CT scan.

Additional tests

Blood in the urine, either visible or even invisible, may need various other tests to look for the cause of the blood in the urine. The tests that will be conducted will be focused to the suspicion of the underlying disease, as well as based on a risk-based approach, and generally includes at least a CT scan and a cystoscopy.

The various tests may include:

Blood test

A blood test is done to evaluate kidney function.

Other blood tests may be done detect signs of autoimmune diseases, such as lupus, or other diseases such as prostate cancer, which can cause hematuria.

Computed tomography (CT) scan

CT scans are done to visualize images of the urinary tract, especially the kidneys. A solution to drink and an injection of contrast medium may be given for this procedure. This is just a diagnostic test and does not need anesthesia. CT scans can help a doctor diagnose stones in the urinary tract, obstructions, infections, cysts, tumors, and traumatic injuries.


Cystoscopy is a minor procedure that a urologist does to see inside the patient’s bladder and urethra using fibre-optic camera system. The procedure is relatively painless, probably mild discomfort, and is done with anesthetic gel. A cystoscopy can detect cancer in a patient’s bladder.

CT scans or x-rays are unable to detect bladder cancers, especially when they are early. Cystoscopy is a very important procedure done for patients who have blood in the urine.

Kidney biopsy

Kidney biopsy is only indicated in very specific conditions only when there is a suspicion of a primary kidney disease and is not part of the regular general investigations for blood in the urine. This is a procedure that involves taking a small piece of tissue from the kidney. Usually the nephrologist performs the biopsy in an outpatient center or a hospital. The biopsy can help diagnose if the hematuria is due to kidney disease.


Hematuria is a symptom and not a diagnosis or a disease.

The treatment of hematuria would be the treatment for the underlying cause of blood in the urine, i.e. the treatment of stones, cancer, infection, etc.

If during initial evaluation there was no obvious cause for the blood in the urine, then you may require to be on a surveillance for the next 2-3 years as per the current guidelines, as early tumors may not be very obvious and may be small in the initial evaluation and will be difficult to detect in the CT scan.

When to see your doctor

Hematuria (blood in the urine) is a very important symptom. As per current guidelines, if you have blood in the urine, you will have to see a urologist preferably within 2 weeks of onset of the symptoms.

Anyone with hematuria need to be properly evaluated important causes of hematuria ruled out early.

Take Home Message

Hematuria (blood in the urine) is a very important symptom. As per current guidelines, if you have blood in the urine, you will have to see a urologist preferably within 2 weeks of onset of the symptoms.

Anyone with hematuria need to be properly evaluated and important causes of hematuria ruled out early.

The evaluation consists of upper tract imaging (CT Urography with contrast) AND cystoscopy (endoscopy of your bladder).

Practice-pattern assessments have demonstrated significant deficiencies in the evaluation of patients presenting with hematuria.

One study found that less than 50% of patients with hematuria diagnosed in a primary care setting were subsequently referred for urologic evaluation.

The underuse of cystoscopy, and the tendency to rely solely on imaging for evaluation, is particularly concerning since the vast majority of cancers diagnosed among persons with hematuria are bladder cancers, optimally detected with cystoscopy.

Other links and websites to get further information on hematuria: