BPH LUTS

Garden hose strangled by a growing vine

Imagine a garden hose (the urethra) that starts out wide and flexible, carrying water freely from a holding tank (the bladder) to the garden. Over years, a vine (the enlarging prostate transition zone) slowly wraps around the hose, squeezing it tighter. At first, the pump (the detrusor muscle) just works harder, building up pressure to force water through the tightened section—this works for a while, so you might not notice anything wrong. But the harder the pump works, the thicker and stiffer its rubber becomes (hypertrophy and decreased compliance), until eventually it cannot stretch to hold a full tank anymore and feels uncomfortably full at half capacity. The pump also starts spasming (detrusor overactivity) from the strain, ejecting small amounts of water at irregular times whether you wanted to or not. Finally, after years of high pressure, the pump wears out (decompensation)—it cannot squeeze hard enough to empty the tank completely, so water pools in the bottom (post-void residual), grows bacteria, and backs up the inlet pipes into the storage tanks behind it (hydronephrosis and kidney damage). That single strangling vine at the hose caused every downstream problem.