How to Check if the Prostate is Large
Perform a digital rectal examination (DRE) to directly assess prostate size—an enlarged, soft, non-tender prostate on DRE is the hallmark finding for benign prostatic enlargement. 1, 2
Physical Examination Technique
Digital rectal examination is the primary method to assess prostate size clinically. The examination should evaluate prostate size, consistency, and exclude nodules or induration that would suggest prostate cancer. 1, 2
An enlarged prostate on DRE typically feels soft and non-tender in benign prostatic hyperplasia, distinguishing it from prostate cancer which presents with a hard, nodular, or indurated gland. 2
The DRE provides immediate clinical assessment of prostatic enlargement and is part of the required initial evaluation recommended by the American Urological Association. 1, 3
Complementary Diagnostic Measures
Symptom Assessment Tools
Administer the International Prostate Symptom Score (IPSS) or AUA Symptom Index to objectively quantify symptom severity and bother, which guides treatment decisions. 4, 1
The IPSS evaluates both obstructive symptoms (weak stream, hesitancy, intermittency, straining, incomplete emptying) and irritative symptoms (urgency, frequency, nocturia) on a standardized scale. 4, 5
Objective Measurements
Uroflowmetry objectively assesses voiding function and establishes baseline flow parameters, with improvements in maximum urinary flow rate (Qmax) indicating reduced obstruction. 1
Post-void residual (PVR) urine volume measurement using bladder ultrasound assesses bladder emptying efficiency and detects urinary retention. 1
Laboratory Testing
Urinalysis is essential to exclude infection, hematuria, or other pathology in the diagnostic evaluation. 1, 2
Serum PSA measurement should be offered in men with greater than 10-year life expectancy, both to exclude prostate cancer and to predict BPH progression risk. 1, 2
Advanced Imaging (When Indicated)
Transrectal ultrasound or MRI can quantify prostate volume precisely, but should be limited to situations where results will benefit the patient, such as in selection for surgery. 4, 6
Prostate volume assessment by imaging is particularly useful when considering 5-alpha reductase inhibitor therapy, which is most effective for prostates larger than 30cc. 1, 7
In clinical trials, finasteride reduced prostate volume by 17.9% over 4 years in men with baseline volumes ranging between 40-50cc, as measured by MRI. 6
Critical Clinical Pitfalls
Do not rely solely on symptoms to determine prostate size—symptom severity does not always correlate with the degree of prostatic enlargement. 4
Do not order routine upper tract imaging or cystoscopy in uncomplicated presentations—these tests have specific indications such as hematuria, stones, or prior surgery. 1
Do not assume all lower urinary tract symptoms are due to prostatic enlargement—LUTS can result from bladder dysfunction, neurological conditions, or systemic diseases like heart failure or diabetes. 8, 9
The terminology "benign prostatic hyperplasia" technically refers to histological findings, while "benign prostatic enlargement" describes gland enlargement based on clinical assessment by DRE. 2