Hematuria = blood in the urine


You will find information on hematuria which is not associated with recent urologic surgery on this page. For information on how to manage hematuria associated with recent surgery, please check the Procedures and Surgery page. If the hematuria is associated with previous or recent urological surgery such as transurethral resection of the prostate or kidney stones, the causes and evaluation are often quite different than what is presented here.




Hematuria, or blood in the urine, is a common reason for someone to be referred to a urologist. Blood in the urine is usually reported as either:

  1. MICROSCOPIC hematuria: invisible to the naked eye but detectable with either a urine dipstick or microscope
  2. GROSS hematuria: visible to the naked eye, sometimes accompanied by clot

While hematuria can be a sign of problems with the filtration/concentration functions of the kidney, it is most commonly from 'structural' abnormalities within the renal parenchyma (the 'meat' of the kidneys) or from the urinary tract (the collection of pipes and surrounding structures that carry urine from the kidneys to the bladder for storage and eventual discharge through the urethra from the body). For this reason, urologists rather than nephrologists typically evaluate hematuria (nephrologists are medical specialists are primarily concerned with the filtration/concentration functions of the kidney and this is usually not the cause of blood in the urine).



Cancers may bleed intermittently. Never ignore even a single event of blood in ther urine. Blood in the urine is never normal. If you have cancer, you want to catch it early.

Never assume that blood in the urine is normal EVEN if you are on a blood thinner (anti-platelet medications, anticoagulation, thrombolytics). These medications can amplify the amount of blood from underlying disesase (e.g. prostate problems, infections or cancer) but do NOT cause bleeding by themselves.




Hematuria, especially gross hematuria, can be a presenting sign of BLADDER CANCER or KIDNEY CANCER and should never be ignored. 


There are literally hundreds of possible reasons for hematuria, but only a handful of worrisome causes that need to be ruled out. The most common causes for hematuria are urinary tract infections, kidney stones, benign growth of the prostate and cancers involving the lining of the urinary system, especially of the bladder (urothelial cancers). In many cases, a cause will not be found and this is referred to as idiopathic benign hematuria.


While up to 5% of the normal adult population has microscopic hematuria at any given time, only about 5-10% of them will have significant pathology on assessment. The chances of finding a serious cause can approach 50% if the blood is visible and there is a history of smoking. The major risk factors for a serious cause such as a bladder cancer (the most common and serious cause of hematuria) or a kidney cancer (a serious but less common cause of hematuria) increases with:


  1. Visible blood (Gross hematuria)
  2. Increasing age (especially over 50-60)
  3. Male gender
  4. Caucasian ethnicity
  5. Smoking history
  6. Certain exposures: e.g. specific occupational exposures, chemotherapeutic agents, or radiation


Diagnosis & Evaulation


Depending on your situation, your urologist may recommend a number of tests to rule out a potentially important cause. The general diagnostic approach is to tailor the evaluation to exclude  serious causes as best as possible. The evaluation is tailored to the patient's risks and clinical evaluation. This always starts with a history and physical examination followed by investigations targeted at the upper tracts (kidney, renal pelvis and ureters) and lower tracts (bladder and urethra). The commonly used tests include:


  1. CYSTOSCOPY: required in all patients with rare exception* - this is a quick test lasting a few minutes that is THE test to check for bladder cancer
    1. Urine microscopy: at least a couple of urine tests to confirm >3 red blood cells (RBC) is required; a dipstick can show hemoglobing, but this may not be freom RBC's in the urine
    2. Urine cytology: this may be helpful in defining the presence of cancer in some situations but a 'negative' cytology (i.e. no cancerous cells seen) is NOT sufficient to exclude the presence of bladder cancer - therefore a cystoscopy is almost always required
  3. BLOOD TEST: creatinine to check kidney function
  4. IMAGING: this is up to the discretion of the Urologist but in general it is usually ultrasound for microhematuria and CT IVP for gross hematuria


*Cystoscopy is the most important test because it is the only test which can exclude the presence of bladder cancer with certainty. There are few exceptions to doing a cystoscopy - in general, the only patients who do not require cystoscopy are females less than about 35-40 years of age with clear evidence of another cause (for example, bladder infection)


Urine Cytology: Urothelial cells are continually shed from the lining of the bladder and cancerous cells may show up in his tests.  Urine cytology is a test which evaluates the appearance of urothelial cells for cancer. There are limitations in that cancer cells may not be found in the urine if the urine is very dilute, the tumor is of lower grade or smaller in size. Therefore, a 'negative' urine cytology test cannot exclude the presence of urothelial cancer.


Two common imaging tests are used to evaluate the upper tracts. An ultrasound is an excellent test to check for tumors of the kidney and can reasonably exclude the presence of obstruction or a stone. It is, however, poor add excluding tumors of the renal pelvis and ureters. Fortunately, such tumors are rare but are more common in patients with gross hematuria or multiple risk factors for urothelial carcinoma. Therefore a CT IVP is performed in patients with gross hematuria or high-risk features as they can evaluate the kidney itself and the upper tract collecting system. A CT IVP is not necessary in the vast majority of patients with microscopic hematuria.




The treatment of hematuria is directed at the cause. You may find more information on the common causes of hematuria such as kidney stones, benign prostatic enlargement and bladder cancer on the Urologic Conditions page.


Hematuria in of itself can produce a number problems such as anemia or the development of clots in the upper urinary tract which can produce obstruction (with symptoms very similar to kidney stones) or in the lower urinary tract. In the vast majority of people, the amount of blood loss is minimal but can appear large simply because the blood has been diluted in urine. Blood clot which forms in the bladder can obstruct the bladder outlet and urethra and cause urinary retention. This may require a catheter to flush the blood out. In order to reduce the chances of blood clot formation, increased fluid intake and frequent urination is advised.




If a specific cause was found during testing, your urologist will provide advice to address the particular condition.


If NO abnormality is found (so called 'idiopathic hematuria'), there are several options. None of the guidelines from the American Urological Association or Canadian Urological Association specify what the optimal follow-up is - but in general, the follow-up should be tailored to the patient. Patients who had very little risk of having a serious condition to start (for example, younger patients, females, those with no history of smoking) may not require any follow-up. Those patients who remain at increased risk of developing a serious condition (especially cancer) may require a repeat scope, urine tests and even imaging and/or cystoscopy. 


The current 'expert' opinion/consensus is:

  1. Asymptomatic microhematuria with a normal evaluation: no follow-up if very low risk, alternatively annual urine analysis x 2 years
    1. if no blood for 2 years, discharge from follow-up
    2. if blood persists, consider repeat cystoscopy and imaging within 3-5 years
  2. Gross hematuria with a normal evaluation: repeat a urine analysis yearly for a couple of years


On the Web

BC Ministry of Health Hematuria Guidelines

AUA Patient brochure on hematuria

America Urological Association Guidelines on Asymptomatic Microhematuria

Cleveland Clinic information

General Urology Websites

Canadian Urological Association  Extenstive library of downloadable pamphlets on a wide range of urological conditions

Cleveland Clinic

Mayo Clinic

Medline Plus Produced by the US National Institutes of Health with information on virtually every health topic and extensive list of links

UrologyHealth.org The patient information site of the American Urological Association.