From the Guidelines
Hematuria, or blood in the urine, can be caused by numerous conditions affecting the urinary tract, including urinary tract infections, kidney stones, enlarged prostate, strenuous exercise, kidney disease, bladder or kidney cancer, certain medications, and inherited disorders. The causes of hematuria can be divided into nephrogenic and urogenic causes, with renal parenchymal disease being the most common benign nephrogenic cause, and common benign urogenic causes including urolithiasis, infection, and benign prostatic hypertrophy 1. Some of the key factors associated with the development of a urinary malignancy include gross hematuria, male gender, age >35 years, smoking, occupational exposure to chemicals, analgesic abuse, history of urologic disease, irritative voiding symptoms, history of pelvic irradiation, chronic urinary tract infection, exposure to known carcinogenic agents or chemotherapy, and chronic indwelling foreign body 1. The evaluation of hematuria typically includes urinalysis, imaging studies, and possibly cystoscopy depending on the specific symptoms and risk factors, with the goal of identifying the underlying cause and providing appropriate treatment to improve morbidity, mortality, and quality of life. Some key points to consider in the evaluation of hematuria include:
- Gross hematuria has a high association with malignancy, and all patients with gross hematuria should have a full urologic workup 1
- Patients with microhematuria have a low risk of malignancy, but may still require evaluation to rule out underlying conditions 1
- The use of anticoagulant therapy does not alter the urologic evaluation of microhematuria 1
- Patients with suspected urinary tract infection as a cause of microhematuria should have urine cultures performed to confirm an infection 1
- Patients with a suspected cause of microhematuria, including interstitial cystitis or benign prostatic hyperplasia, should have the appropriate clinical workup before undertaking imaging 1. Overall, the evaluation and management of hematuria should be guided by the principles of minimizing morbidity, mortality, and improving quality of life, with a focus on identifying and treating the underlying cause of the condition.
From the Research
Causes of Hematuria
The causes of hematuria (blood in urine) can be varied and range from benign conditions to serious diseases. Some of the potential causes of hematuria include:
- Infection 2, 3, 4
- Kidney stones 2, 5, 4
- Trauma 2
- Exercise 2
- Spurious causes, such as foods, drugs or menstruation 2
- Tumors, including bladder cancer, upper urinary tract urothelial cell carcinoma (UUT-UCC), and renal cell cancer 2, 5, 4
- Vascular diseases involving the upper urinary tract 6
Urological Causes
Common urological causes of hematuria include:
- Urinary tract infection 4
- Ureteric and renal stones 4
- Concurrent pathology should be suspected if haematuria is significant or persistent 4
Diagnostic Approach
The diagnostic approach to hematuria involves answering several key questions, including:
- Is it really hematuria? 3
- Should this patient with hematuria be worked up, and if so, how? 3
- Should this patient with hematuria be referred, and if so, to which specialty? 3 Recommended investigations for haematuria include:
- Computed tomography intravenous pyelogram 4
- Urine cytology 4
- Urine microscopy and culture 4
- Blood tests (full blood examination, renal function and, in men, prostate-specific antigen) 4