Turbulent urinary flow in the urethra could be a causal factor for benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is the most common form of prostate disease in middle-aged and elderly men, and leads to severe impairment later in life. Despite its significant impact on public health, the underlying cause of BPH is yet to be determined. This hypothesis proposes a new causal factor for BPH. Applying concepts of dynamics of fluids to the process of urination it could be stated that a turbulent urinary flow through the passage of the urethra. The turbulent urinary flow in the urethra applies pressure and stretch forces to the surrounding tissue. This stimulus repeated over time and coupled with age-related changes of the urethral tissue could contribute to the development of BPH. In support of this hypothesis, several mechanotransduction studies have shown that vibration and pressure forces applied to different cell tissues can provoke cellular and molecular changes. Another supportive data is the presence of the hyperplasic reaction surrounding the urethra specifically located in the transition zone, the only zone where BPH develops. It is crucial to identify causal factors to understanding the disease and to determine effective primary prevention strategies. Future studies of the dynamics of fluids in the urethra are warranted. The finding of significant forces transmitted to the periurethral tissue from a turbulent urinary flow could give us the clue to the underlying cause of BPH. If this hypothesis proves to be valid there are several primary prevention measures that could be implemented to impede the development of BPH. Educational intervention measures in younger populations to avoid frequent urinary retention and active urination (process of forcing the urine through the urethra at a high velocity) could be considered. Studies of the impact of turbulence in the standing vs. sitting position during urination in men should also be considered.