Hematuria refers to the presence of blood in the urine and is usually caused by bleeding somewhere in the urinary tract. Hematuria may be caused by several health conditions as well as the use of certain medications.

Some examples of the causes of hematuria include:

• Infections – Hematuria can be caused by infections of any part of the urinary tract, referred to as urinary tract infections (UTIs).

Infection may be present in the kidneys, the tubes that carry urine from the kidneys to the bladder (ureters), or the tube that carries urine from the bladder out of the body (urethra).

Infection of surrounding organs such as the prostate (prostatitis) may also lead to hematuria.

• Injury or trauma to any part of the urinary tract may cause blood to leak into the urine.
• Kidney or urinary tract stones are the most common cause of hematuria in people aged under 40 years.
• Polycystic kidney disease damages the kidneys, which can lead to hematuria
• Cancers of the urinary tract such as kidney cancer or bladder cancer give rise to hematuria.
• Benign hyperplasia of the prostate or BHP is a common cause of hematuria in men aged over 50 years.
• Prostate cancer can also lead to hematuria.
• The abnormal formation of blood clots in certain blood clotting disorders such as haemophilia causes hematuria.
• In sickle cell disease, abnormal, crescent-shaped red blood cells block the smaller blood vessels, disrupting blood flow and leading to hematuria.
• Ureteral pelvic junction obstruction (UPJO) is a rare, congenital condition where blockage of the ureter leads to hematuria.
• Left renal vein hypertension is a rare blood vessel abnormality called the “nutcracker syndrome” that gives rise to hematuria.
• Some drugs may also cause hematuria. These include quinine, sulphonamides and the antiepileptic drug phenytoin.