Benign prostatic hyperplasia (BPH) is a common disease in older men whose main clinical manifestation is lower urinary tract symptoms (LUTS). LUTS can cause depression and decreased quality of life, and in severe cases can lead to acute urinary retention and pyuria. One of the potential risk factors for LUTS is prostate volume. In all studies to date, there is controversy as to whether prostate volume is positively correlated with symptom severity in patients with an International Prostate Symptom Score (IPSS) greater than 8, and there is a gap in research for men with mild and asymptomatic lower urinary tract symptoms (IPSS <8). In view of this, Prof. Ross et al. of Duke University aimed to investigate the correlation between prostate volume and LUTS in men with IPSS <8. The study was published in the 2015 issue of Eur Urol. The REDUCE study, initiated by Professor Gerald and others at the University of Washington School of Medicine, is a large, multicenter, randomized, double-blind, placebo-controlled study to investigate whether dutasteride reduces the incidence of prostate cancer. Professor Ross et al. performed a post hoc comparative test of the effect of prostate volume on the incidence of LUTS in 3090 patients with an IPSS <8 in the REDUCE study. These patients had a PSA between 2.5 and 10 ng/ml and a negative prostate puncture biopsy; Ross et al. defined LUTS as being caused by BPH and having an IPSS >14 or requiring pharmacological or surgical treatment for worsening symptoms during the study period. The risk of LUTS in men with prostate volumes between 40.1 and 80 ml was found to be 1.67 times higher in the placebo group than in men with prostate volumes below 40 ml, with no significant difference in the oral dutasteride (0.5 mg/day) group. This leads to the conclusion that in men with mild and asymptomatic lower urinary tract symptoms, the larger the prostate volume, the higher the risk of LUTS, whereas in men taking dutasteride, the prostate volume was not associated with the incidence of LUTS. It is well known that rectal examination is a convenient and widely used clinical test that can determine whether the prostate is large, although it cannot accurately measure the volume of the prostate. The study by Prof. Ross et al. found an increased risk of LUTS in mildly symptomatic men with a large prostate (>40 ml). Thus, the risk of LUTS can be determined at an early stage by rectal examination, and early preventive measures can be taken.