From the Guidelines
Hematuria, or the presence of blood in urine, is a condition that requires immediate medical attention, as it can be a symptom of various underlying conditions, including urinary tract infections, kidney stones, enlarged prostate, kidney disease, and cancer of the urinary tract. The causes of hematuria can be divided into nephrogenic and urogenic causes, with renal parenchymal disease being the most common benign nephrogenic cause, and urolithiasis, infection, and benign prostatic hypertrophy being common benign urogenic causes 1.
Common Causes of Hematuria
- Urinary tract infections
- Kidney stones
- Enlarged prostate
- Kidney disease
- Certain medications
- Strenuous exercise
- Cancer of the urinary tract
According to the American College of Radiology, patients with gross hematuria have a high association with malignancy, and therefore, all patients with gross hematuria should have a full urologic workup 1. On the other hand, patients with microhematuria have a low risk of malignancy, and in most patients with asymptomatic microhematuria, a cause is never found 1.
Evaluation and Treatment
The evaluation of hematuria should include a thorough history, physical examination, urinalysis, and serologic testing prior to any initial imaging 1. Imaging modalities such as ultrasound, CT, and MRI may be used to evaluate hematuria, and treatment depends entirely on the underlying cause, which may include antibiotics for infections, pain management and hydration for kidney stones, or specific interventions for other conditions 1.
It is essential to seek medical attention immediately if you notice blood in your urine, especially if accompanied by pain, fever, or difficulty urinating, and to avoid self-medicating with over-the-counter products that may interfere with diagnostic testing. While waiting for medical attention, it is recommended to drink plenty of water unless instructed otherwise by your doctor 1.
From the Research
Causes of Hematuria
The presence of blood in urine, also known as hematuria, can be caused by various factors. Some of the possible causes include:
- Medications: Anticoagulants such as warfarin can increase the risk of hematuria, as seen in a patient who developed hematuria while taking warfarin 2
- Infections: Urinary tract infections (UTIs) can cause hematuria, with Escherichia coli being the most frequently isolated microorganism from urine cultures 3
- Kidney or bladder problems: Conditions such as kidney stones, bladder cancer, or schistosomiasis can cause hematuria 2, 4
- Trauma: Injury to the kidneys or bladder can cause hematuria
- Certain medications: Trimethoprim/sulfamethoxazole can cause acute kidney injury, which may lead to hematuria 5
Underlying Pathology
Hematuria can be a sign of underlying pathology, and timely evaluation is necessary to identify and treat clinically important conditions. For example, a patient with hematuria was found to have transitional cell carcinoma of the bladder 2, while another patient was diagnosed with schistosomiasis, which mimicked bladder cancer 4
Evaluation of Hematuria
The evaluation of hematuria should include renal function testing, urinary tract imaging, and cystoscopy, especially in the absence of obvious causes 6. Urinalysis alone may not be sufficient to establish a diagnosis, and further testing may be necessary to determine the underlying cause of hematuria.