Hematuria or having blood in the urine always creates a lot of alarm to the patient as it is a very bulky symptom. It is important to initially assess whether due to its importance it requires hospital admission (anemia) or it can be controlled through an outpatient study.
The appearance of hematuria is a sign or indicator of bleeding in the excretory or renovesical route. It can be appreciated with the naked eye, in which case we will speak of macroscopic hematuria or that is negligible to the human eye and, in this case, we will speak of microscopic hematuria or microhematuria. Microhematuria is considered to exist when more than 3 red cells per field are quantified in a urine sediment.
Some of the symptoms that frequently accompany hematuria are: pain (suprapubic or when urinating), discomfort when urinating (burning), increased frequency of urination (frequency), difficulty urinating, emission of little urine during urination (oliguria), fever, poor general condition …
How is it diagnosed
- The first test that is requested is a test strip that turns color when it comes into contact with the urine. Different parameters can be analyzed: red blood cells, proteins, leukocytes, pH …). The color will be more intense depending on the concentration of each of the parameters analyzed. In this way we can confirm if there is blood in the urine and the approximate amount of red blood cells. The urine strips have a sensitivity of approximately 70% and a high specificity.
When the test strip is positive (red blood cells are detected), a urinalysis ( urinalysis ) should be performed where the red blood cells are accurately quantified . If a urine infection is detected , antibiotic treatment is usually given , although, if the infection is recurrent, we may request a urine culture to identify the causative germ.
- Likewise, a general blood test is requested , in whose hemogram we will verify if there is anemia (it will indicate the loss of red blood cells as a consequence of hematuria) and we will also assess the renal function parameters (urea and creatinine).
Once confirmed, the cause is studied
Red blood cells can come from any anatomical structure in the urinary tract. Once hematuria is confirmed, the study should be started to find out its origin. It is important to emphasize that the presence of hematuria does not necessarily equate to a malignant disease . Some causes of hematuria are benign and transient and resolve spontaneously or with specific medical treatment.
- An infection (for example, hemorrhagic cystitis),
- A prostate problem (for example, benign prostatic hypertrophy or prostatitis)
- A tumor of the urinary tract (for example, urinary bladder)
- Presence of kidney stones (stones or stones in the kidney or ureters).
- Other possible causes are intense exercise, kidney diseases that affect the filtration of the renal glomerulus, trauma, the intake of certain medications such as anticoagulants, the intake of beets …
Patient evolution and diagnostic tests
The evaluation of the patient with hematuria includes taking a detailed medical history with a physical examination and complementary tests. During the history, it is important to investigate the characteristics of hematuria. If hematuria appears at the beginning of urination, we will suspect a urethral origin , if it appears at the end of urination, it suggests a bladder origin and when it appears during the entire urination it may be from the kidneys, ureter or bladder .
- The first diagnostic imaging test that is usually ordered is a renovesical ultrasound that will assess the urinary tract from the kidney to the urinary bladder. If a kidney injury is detected when performing it, a computed tomography or scanner (UroTAC) with high sensitivity and specificity to detect kidney and upper urinary tract injuries will be requested . In this case, the follow-up will be carried out by an expert in Nephrology.
- If the kidney is undamaged or lower urinary tract pathology is suspected, the study will continue. For this, the patient’s history will be taken into account (if he is a smoker, if he has been exposed to carcinogenic products, if he had a previous pathology, if he is diabetic or hypertensive…). In the case of a patient with any of these risk factors, a cystoscopy will be requested . If you do not present risk factors, cytology is usually chosen (to evaluate if there are abnormal cells in urine).
- After the ultrasound study, the tests most frequently requested in the study of hematuria are cytology, cystoscopy and computed tomography or scanner (UroTAC). The imaging test requested will depend on the impression or diagnostic suspicion after the initial evaluation and the resources available.
The diagnosis is not always concluded after performing the aforementioned tests. Sometimes hematuria should be monitored by yearly urinalysis and, depending on the evolution of the values, it will be decided whether it needs to repeat any of the imaging tests already performed previously. However, if the hematuria disappears in subsequent controls, the follow-up will be concluded.
What you should know…
- The appearance of spontaneous hematuria generates an alarming situation. That is why it is a very frequent reason for requiring a visit in hospital emergencies.
- The presence of hematuria does not necessarily equate to a malignant disease. Some causes of hematuria are benign and transient and resolve spontaneously or with specific medical treatment.
- The diagnosis is not always concluded after performing the aforementioned tests. Sometimes hematuria should be followed up. However, if it disappears in subsequent controls, the follow-up will be concluded.