Seeing blood in your urine can be alarming. While in many instances the cause is harmless, blood in urine (hematuria) should be taken seriously as it can indicate a serious underlying disease.
Blood in the urine also know as hematuria, is a symptom of an underlying issue in the urinary tract. The blood loss is usually not heavy, so the main concern is diagnosing the underlying cause
Blood in the urine may painless or may be accompanied by other symptoms.
Contrary to popular belief, painless visible blood in the urine is actually the more alarming situation. This is because cancers of the urinary tract such as of the kidney, bladder or prostate cancer do not cause pain unless at a very advanced stage.
Blood in the urine that is accompanied by pain on urination is commonly caused by an urinary tract infection (UTI). If haematuria is associated with pain in the back or abdomen, this may be caused by a kidney or ureter stone.
Reddish urine may sometimes not be caused by blood. This is called pseudohematuria.
Pseudo-haematuria may be caused by the following:
It is important to see a doctor to check if the red coloured urine is caused by blood in the urine rather than hope or assume that it is pseudohematuria.
Blood in the urine is not usually an emergency, unless the urine is very dark red and has large clots. In that situation, there is a significant loss of blood, and the clots may cause blockage of urination.
There are many causes of blood in the urine:
Runner’s bladder occurs in long distance runners running typically more than 10km. It is theorised that this occurs when the back part of the empty bladder repeatedly strikes the front part of the bladder, traumatising the inner lining of the bladder causing bleeding. This may be avoided by passing urine more than half an hour before running, so that the bladder is partially filled with urine during the run and cushions the bladder walls.
March hematuria occurs when blood is seen in the urine after repetitive impacts on the body, particularly affecting the feet. The word "march" is in reference to the condition arising in soldiers who have been marching for long periods. The repetitive trauma causes the red blood cells to burst and the pigment of the red blood cells are filtered in the kidney and give the urine a brownish colouration.
Investigation of people with exercise-induced blood in the urine sometimes finds underlying urinary tract injury or disease. Therefore, if you see blood in your urine after exercise, don't assume it's from exercising. See your doctor.
Blood in the urine can be intermittent and can resolve spontaneously. However, this does not mean that the underlying condition that caused it has resolved. This is why even a single episode of visible blood in the urine needs to be assessed. Sometimes kidney and bladder cancers only bleed once, and the next time it bleeds, the tumour has already progressed to a more advanced stage.
Visible blood in the urine is often attributed to infection, especially in women as they are more prone to urinary tract infections (UTI). This is reasonable if the blood in the urine comes with typical symptoms of UTI like burning pain when passing urine, or frequent urination with urgency. However, if the blood in the urine is painless, it should not be blamed on UTI. While it may disappear after taking antibiotics, this may a coincidence rather than proof that it was caused by a UTI, as bladder/kidney tumours can bleed intermittently and stop spontaneously.
Bladder cancer is more common in men, but women with bladder cancers have a worse outcome. This is because women with bladder cancer often have delayed diagnosis and are found at a more advanced stage because their initial episodes of haematuria are attributed to UTI and they treated with a number of courses of antibiotics rather than being referred to specialist for further evaluation. In comparison, men with a single episode of visible haematuria are usually referred to urologists for further evaluation.
If the bleeding is significant, the blood in the urine may form clots which can cause blockage of urine flow. This can lead to blockage of the kidney or the sudden painful inability to pass urine (acute urinary retention). A tube will then be needed to be inserted to bypass the blockage.
If the bleeding is persistent, one can lose enough blood to become anemic. If severe cases, the sudden loss of large amount of blood can lead to low blood pressure and shock. This is obviously an emergency, but is thankfully a rare presentation.
Oftentimes, blood in the urine is not visible to the naked eye, but found on testing of the urine with a dipstick or under microscopic examination. These tests may be done during follow up for chronic medical conditions such as hypertension or diabetes, or during health screenings.
This is called microscopic haematuria. Incidental microscopic haematuria that is not associated with any urinary symptoms is very common – as many as 20% of the population may harbour microscopic haematuria.
The significance of this is that it may be an early signal of the presence of the same underlying conditions that cause visible hematuria. On detailed checkup, as many as 5% of those affected will be found to have significant urinary tract disease like stones or cancer. However, doctors cannot tell which of the people with microscopic haematuria have these diseases without further checkup. I would recommend that if you have been found to have microscopic haematuria, that you ask your doctor to repeat the test with a microscopic examination of the your urine. If the repeat test is positive for blood, then you should be seen by a urologist to determine if further investigation is required.
It is important to note that just because the blood in the urine is microscopic does mean that the underlying cause is minor. I have found large bladder cancers in patients that only had microscopic haematuria and no other symptom.
You will be asked questions to determine if you have other symptoms that may point to an underlying cause of the blood in the urine. Risk factors for serious underlying conditions such as a history of cigarette smoking will be checked
Urine tests may be done to confirm the presence of blood in the urine, as well to check for urine infections. For men, a blood test (PSA) may be done to exclude prostate cancer.
Scans of the urinary tract such a CT scan or ultrasound to look for stones/ kidney tumours may be done. If there is a concern for a bladder cancer, a cystoscopy to check the inner lining of the bladder is recommended.
A CT scan is very good for looking for abnormalities in the kidneys and ureters. However, early bladder cancers can be flat or very small, and can be missed on a CT scan. As such, if there is a risk for bladder cancer, you should proceed for a cystoscopy even if the CT scan is negative.
Cystoscopy is done with thin flexible tube with a camera at the end. This is a short procedure that last 2-3min, and is usually done under local anaesthesia with gel introduced into the urethra. There is no need to fast or stay in the hospital, as the procedure is done in our clinic procedure room.
Some people are reluctant to see their doctor when they have blood in the urine because they fear that they may have cancer.
I counsel my patients that it's always better to find cancers earlier rather than later.
Early cancers of the urinary tract are usually curable. Treatments for early cancer are better tolerated and less disfiguring than treatments for late cancer.
For example, early bladder cancer can be removed by endoscopic surgery through the urethra with no scars on the body. On the other hand, more advanced bladder cancer may need chemotherapy followed by a large 15cm cut in the abdomen to remove the bladder, and I will need to create a new tube (ileal conduit) from a piece of intestine to allow the kidneys to drain and urine to exit the body through a small opening in the abdomen.
Blood in the urine can be an alarming symptom. It is often a sign of an underlying disease of the urinary tract. Diagnostic tests are not painful. Early diagnosis can lead to early cure and prevent a bad outcome.