Popliteal artery entrapment syndrome occupies a frustrating corner of vascular medicine. It overwhelmingly affects young, physically active people — the demographic that doctors tend to reassure first and investigate last.

If you are a runner, cyclist, or military athlete who feels a building pressure, burning, or numbness in your lower legs during exercise — symptoms that vanish within minutes of stopping and return every time you push past a certain threshold — you are already familiar with how difficult this experience is to explain.