Asymptomatic Hematuria - Causes, Symptoms, Diagnosis, and Management

Introduction

Hematuria is a condition when blood occurs in the urine. Hematuria is usually of two types; gross hematuria, where blood can be seen, and microscopic hematuria when blood cannot be seen in the urine unless tested or detected in a microscope. Microscopic hematuria is also called microhematuria or asymptomatic hematuria. Asymptomatic hematuria usually occurs in children and adults, and sometimes it can resolve on its own or be due to certain treatable conditions. The blood in the urine can arise from any site of the urinary tract, whether gross or microscopic; it can also be a sign of an underlying malignancy.

Since asymptomatic hematuria has causes ranging from minor findings that do not require any treatment to highly significant conditions that can be threatening, they are divided into three categories: life-threatening- which are significant and requires treatment; then significant, which requires observation and insignificant.

Asymptomatic microscopic hematuria refers to two, three or more red blood cells in a high-power microscopic field of urinary sediment from a minimum of two properly collected urine analysis specimens. This definition accounts for the intermittent nature of hematuria in people with urinary malignancies and some degree of hematuria in normal people. In patients with asymptomatic microscopic hematuria, the American Neurological Association recommends an appropriate urological or renal evaluation in patients who have a risk for a primary renal disease or neurological disease.

What Causes Asymptomatic Hematuria?

Asymptomatic hematuria is not usually contagious, and its most common cause includes urinary tract infections. The other conditions that cause asymptomatic hematuria include

• Menstrual cycle.

• Vigorous exercises.

• Certain medications.

• Kidney diseases.

• Enlarged prostate or benign prostatic hyperplasia.

• Urinary tract stones, including kidney stones, bladder stones, and urethral stones.

• Urethral strictures.

• Cancer of the kidneys, bladder, and prostate.

• Asymptomatic hematuria can also cause due to an underlying benign or malignant tumor of the urinary tract.

What Symptoms Are Seen in Asymptomatic Hematuria?

No symptoms are usually seen in asymptomatic hematuria. If any symptoms occur, they include fever, foul-smelling urine, frequent urination, pain or burning sensation while urinating, and pain in the back or the side area.

What Is the Prevalence of Urinary Tract Malignancies in Asymptomatic Hematuria?

Asymptomatic hematuria is a significant clinical sign of urinary tract malignancies. Bladder cancer is estimated to occur in men 3.3 times more than in women. Bladder cancer is the fourth most commonly occurring cancer in men, and it occurs in almost 6% of cases, whereas bladder cancer occurs only two percent in females and is not in the top 10 commonly occurring cancers in them. Bladder cancer is also the eighth most common reason for death in men.

What Are the Risk Factors for Certain Diseases in Patients With Microscopic Hematuria?

Certain risk factors for significant diseases that occur in patients with microscopic hematuria include

• History of smoking.

• History of gross hematuria.

• History of urological disease or disorder.

• History of pelvic irradiation.

• History of urinary tract infection.

• History of irritative voiding symptoms.

• Occupational exposure to chemicals or dyes like aromatic amines or benzenes.

• Age above 40 years.

• Analgesic abuse.

How Is Asymptomatic Hematuria Diagnosed?

To diagnose asymptomatic hematuria, the healthcare provider will take a detailed history of past medical issues and current symptoms. The healthcare provider will enquire about the use of tobacco or smoking, weight gain or weight loss during recent times, intake of medicines, over-the-counter supplements, or other recreational drugs, whether the person has had past blood in the urine, and whether any of their family members have had blood in the urine in the past. No evaluation is required if hematuria has resolved. However, patients with persistent hematuria do require evaluation.

Some other tests that the health care provider might order include-

• Urine tests, including urine microscopy and urine analysis. An infection can be found in urine culture. Laboratory tests usually show three or more red blood cells in the high-powered field under the microscope. According to the American Neurological Association, this is the definition of asymptomatic hematuria. Repeating the testing is optional if it is confirmed in the first test. Suppose the history suggests a suspected benign cause for the microscopic hematuria. In that case, the patient should undergo a repeat analysis 48 hours after cessation of activities like trauma, menstruation, vigorous exercises, or sexual activity.

• Blood tests include a complete blood count (CBC) test.

• Kidney function tests evaluate the proper functioning of the kidneys.

• Imaging scans include computer tomography (CT) scans. In patients with asymptomatic hematuria, imaging tests usually detect urolithiasis and renal infection, transitional cell carcinoma, and renal cell carcinoma in the pelvicalyceal system or ureter.

• Cystoscopy is a procedure where a small telescope is inserted to examine the interior portion of the bladder and urethra. Cystoscopy is required since the presence of hematuria is usually an important risk factor for the management of malignancies in certain patients.

How Is Asymptomatic Hematuria Managed?

• Managing asymptomatic hematuria depends on managing its underlying causative factor.

• If tests do not show a specific cause of asymptomatic hematuria, medical intervention is unnecessary and timely observation is recommended.

• Antibiotics will be prescribed if the underlying cause is a urinary tract infection.

• If the person has an enlarged prostate, the doctor will prescribe medications to relax the bladder, shrink the prostate or do both. In some cases, surgical intervention might also be recommended.

• If the person has kidney stones, the health care provider will prescribe medication to relieve pain and relax the tissue in the urinary system to help the stone pass. They can also prescribe anti-nausea medications. In some cases, the best way to manage kidney stones is a surgical intervention which the doctor might recommend if needed.

Conclusion

Asymptomatic hematuria, or microhematuria, is when blood occurs in the urine and can be detected only under a microscope. Healthcare providers can detect the underlying causative factors of this condition through different tests like urine tests, blood tests, imaging tests, and cystoscopy. Depending on the underlying causative factors, the health care provider will recommend medical and sometimes even surgical intervention.