Hematuria is the presence of red blood cells (erythrocytes) in the urine.
If a patient sees blood in the urine, with or without symptoms of cystitis, it is important to seek medical advice immediately. Blood in the urine is usually investigated as a matter of urgency. Most doctors will perform some simple, baseline tests. Antibiotics may be prescribed to treat a presumed infection. However, if the urine test result comes back showing no evidence of infection, a urologist will perform more detailed investigations.
- The commonest cause of blood in the urine is infection (cystitis)
- Some drugs (e.g. rifampicin, nitrofurantoin) and foodstuffs (e.g. beetroot) can turn the urine red and mimic blood in the urine
- Proven blood in the urine, whether visible or non-visible (found on a urine test), should always be investigated
- 1 in 5 adults with visible blood in the urine and 1 in 12 adults with non-visible blood in the urine are subsequently discovered to have bladder cancer
- A "one-off" finding of a small trace of blood in the urine on routine testing may not be significant
Causes of hematuria
50% (half) of patients with visible blood in the urine will have an underlying cause identified but, with non-visible blood in the urine, only 10% will have a cause identified. Although there are many potential causes for blood in the urine, those most common are:
Other, less common causes of hematuria include:
- Bladder infection (cystitis)
- Stones in the kidneys, ureter or bladder
- Prostate Enlargement (also known as benign prostatic hyperplasia or BPH) in older men, especially over age 50
- Cancer of the bladder, kidney or prostate
- Inflammation of the kidneys (nephritis)
- Prostate infection or inflammation (prostatitis)
- Urinary tract injuries
- Blood disorders (e.g. sickle cell disease, clotting disorders, anticoagulant and anti-platelet drugs)
- Other causes, less common infections (e,g. TB, schistosomiasis)
Tests and procedures utilized to diagnose cause of hematuria include:
- A full history asking about any recent symptoms, any associated matters (including any current medications) smoking habits as well as any exposure to industrial chemicals or any exposure to substances that may be related to bladder cancer Patients should inform their doctor if they are taking blood-thinning drugs (warfarin, coumadin) or take anti-platelet treatment (aspirin, dipyridamole, clopidogrel). If the bleeding is painless and associated with clots of blood in the urine, it is likely that urgent referral to a urologist will be advised.
- A physical examination will be performed, together with a rectal or vaginal examination. Measurement of blood pressure may be measured as part of this examination.
- General blood tests to measure kidney function, clotting factors, prostate-specific antigen (PSA) and to check the blood cells for anemia or other problems
- Urine testing for infection and your doctor may commence you on antibiotics whilst awaiting the result of this test.
- Urine cytology Fresh urine may also be sent to the laboratory for microscopic examination, to look for cancerous cells
- 24-hour urine collection to measure your urine protein levels.
- Cystoscopy – With the patient under local anesthesia, a urologist inserts a cystoscope — a slender, flexible tube with a miniature lens and lighting system — through the urethra into the bladder to check for signs of cancer.
- Imaging studies – The urinary tract and surrounding tissue can be imaged by a variety of minimally, or noninvasive, procedures, including: ultrasound scan of kidneys and bladder, (or a CT or MRI scan of the abdomen)
Treatment options will depend on the cause of the hematuria. Assessment of the cause of blood in the urine may not identify a definite cause but it will, normally, rule out significant causes, which require further urological treatment.
No further tests may be required at this stage. In this case, regular monitoring may be recommended to assess the following, which may be signs that re-investigation is needed:
However, if there is visible blood in the urine in the absence of infection, if the blood fails to clear following antibiotic treatment for urinary infection, if the patient has non-visible bleeding but significant urinary symptoms or if persistent non-visible bleeding and the patient is over the age of 40 years, some or all of the following assessments will be performed:
- the development of other urinary symptoms
- further episodes of blood in the urine
- increasing levels of protein in the urine
- progressive deterioration in kidney function
- the development of hypertension (high blood pressure)
This may involve one or more of the following:
- Detailed questioning about urinary tract and any related symptoms
- A physical examination (including rectal or vaginal examination)
- Blood tests (if not already performed)
- Examination of the urine for cancer cells (if not already done)
- X-rays or scans
When the tests have been completed, the medical staff will advise the patient on what to do next:
- CT scan ultrasound scan intravenous urogram (IVU)
IVU and CT scanning involve an iodine-based injection so radiology staff must be informed if the patient has a history of allergy to iodine or to previous X-ray injections.
- A flexible cystoscopy
This is a telescopic check of the bladder and is performed under antibiotic cover & local anesthetic using a small, flexible telescope which allows the urologist to see inside the patient’s bladder. For those who have concerns about this or have experienced problems with local anesthetic in the past, the procedure can also be performed under a brief general anesthetic (i.e. whilst the patient is asleep).
If an abnormality requiring further treatment is detected, the medical staff will advise the patient on what treatment is necessary and what this would involve (e.g. admission for telescopic removal of a bladder tumor).
If no specific abnormality is found, the patients should keep a careful eye on their symptoms and report any further bleeding to their doctor.