Hematuria refers to the presence of blood in the urine. The blood can either be seen with the naked eye (also referred to as gross hematuria) or detected from urine tests (microscopic hematuria).
A person may have microscopic hematuria without realising it. The urine may appear clear when there’s actually blood in the urine. In fact, blood in the urine is not uncommonly detected when a person undergoes urine tests during health screening.
Simple exercises or sexual activity usually do not result in blood in the urine. Hence, in the event of repeated microscopic hematuria or gross hematuria, further evaluation of the urinary tract, which comprises the kidneys, bladder and ureters (tubes that transport urine from kidneys to the bladder), is recommended.
Evaluation can be done in a variety of ways. For the kidneys and ureters, these are usually assessed with radiologic imaging such as X-rays (e.g. intravenous pyelogram) or scans (e.g. CT scans). The bladder is evaluated using cystoscopy, which is direct visualisation of the lining of the bladder. This is accomplished using a fine instrument that is passed from the urine tube opening into the bladder and can be performed in the clinic under local anaesthesia.
Following evaluation, the cause of blood in the urine can usually be ascertained. There are many causes of blood in the urine. The more common causes of hematuria include cancers (e.g. kidney or bladder), stones, infection, etc. Once the cause is determined, treatment can be instituted. For example, kidney cancer can be managed with surgery of whole or part of the kidney. If stones are the cause of hematuria, depending on the size and location of the stone, treatment options include observation, extracorporeal shockwave lithotripsy, intracorporeal laser lithotripsy, etc.
