Haematuria (blood in the urine)
What is haematuria?
Haematuria is a fancy word for blood in the urine. This can be visible to the eye (macroscopic) or not visible (Microscopic or non-visible). These two conditions share similar causes but are investigated slightly differently. Occasionally what looks like blood in the urine can be food based dyes (especially beetroot) or from medication (for example rifampicin)
What causes haematuria?
There are many reasons for blood to be found in urine but surprisingly most times no cause is found for the bleeding. We assume that either a little bit of blood leaks through the kidney when urine is made or that the bladder sheds a little bit of blood with exercise. The most common reason is therefore no cause found, then urinary tract infection, stones and the least common cause is cancer of the bladder or kidney. A full list is given below.
No cause found
Medication (warfarin, dabigatrin)
Intrinsic renal disease
Cancer of the kidney or bladder
Recent throat infection
I smoke does that matter?
People who smoke are more at risk of getting bladder or kidney cancer. You are more likely to have a cancer present if
Have had pelvic radiotherapy
I can't see the blood does that matter?
No you still need to be investigated, although the chance of finding anything wrong is small.
If the blood is not visible to the naked eye then this is called microscopic haematuria or non-visible haematuria. The risk of finding a cancer is lower but you should still be investigated. A positive urine test for blood is
Urine dipstick is ++ or greater or
15 red blood cells or more are found on the urine test.
What tests do I need?
The first thing to do is make sure there is no urinary tract infection present. If there is, then treat this and retest. If the blood disappears after treating the infection no further tests are needed.
Assuming you are feeling well, have had no recent sore throats, no urinary tract infections and are not on rifampicin or eating lots of beetroot then the first investigations are to check your blood pressure and to test for protein in the urine.
If the above tests are normal then the next tests are
For microscopic haematuria an ultrasound and a plain abdominal film
For macroscopic haematuria a CT scan of the kidneys
A cystoscopy (or look into the bladder). This is usually done as a flexible cystoscopy with the patient awake. It is a quick test, which is mildly uncomfortable.
I pee all the time does this matter?
If there is a lot of bladder symptoms (frequent passing of urine) and blood in the urine then it is important to make sure no bladder cancer is present. A urine test for cancer cells maybe asked for (urine cytology). This test is not routine as it is often abnormal when no cancer is present and can also be negative when cancer is found.
Are there any new tests for bladder cancer?
Many companies have looked at new urine tests to try and find bladder cancer. One of these has been developed by a Dunedin company. It is not clear at this stage if the CxBladder test is helpful enough to be worth the money you spend on it.
All my tests are normal but my tests still show blood in the urine, what now?
If the x-rays and cystoscopy are normal, no further testing is needed for most people. You are very likely to have tiny microscopic amounts of blood in your urine forever. Further tests are only needed if you start passing blood that you can see with the naked eye, or you have a lot of bladder symptoms.