What Donguibogam described as a blockage of the water pathways due to weakened kidney qi can be understood in modern medicine through benign prostatic hyperplasia. Found only in men, the prostate gland is a chestnut-sized organ situated directly below the urinary bladder, encircling the urethra. As men age, the prostate gradually enlarges. This common condition begins slowly in one's 40s, affecting roughly half of men in their 60s and more than 80% of men in their 80s.
A primary driver of this enlargement is the conversion of the androgen testosterone into a more potent form called dihydrotestosterone, which stimulates the proliferation of prostate cells. As hormonal balance shifts, the prostate gland grows excessively. This enlarged prostate compresses the urethra, causing symptoms such as a weak or thinning stream, hesitation, interruption of flow, or the need to strain before urine emerges. With increased urethral resistance, the urinary bladder must contract more forcefully to expel urine; over time, the detrusor urinae muscle thickens and becomes irritable. As a result, sudden urgency occurs even when little urine has accumulated, leading to frequent urination and an ongoing sensation of residual urine.
Nocturia, or waking frequently at night to urinate, is one of the most troublesome symptoms of benign prostatic hyperplasia, arising from several overlapping factors. With aging, secretion of antidiuretic hormone decreases, reducing water reabsorption and increasing urine output. In addition, fluid pooled in the lower legs during the day returns to the bloodstream when lying down at night, traveling to the kidneys and further raising nighttime urine volume. Shifts in autonomic nervous system regulation during sleep and bladder irritability can also worsen nocturia. Ultimately, what Donguibogam termed the decline of kidney qi corresponds in modern medicine to clear physical mechanisms: hormonal shifts, prostate enlargement, and urinary bladder hypofunction.
