A gruesome simulation has explained why a pilonidal cyst can be the 'most painful condition' in the buttocks region.

Pilonidal sinus—also called a pilonidal cyst—is a skin infection that occurs in or around the crease of your buttocks. This condition happens when hair, skin cells, and dirt clog a hair follicle, ...

It often starts as a sore spot you assume is a zit, ingrown hair, or minor irritation. Then it gets worse. Sitting becomes uncomfortable. Pressure builds. Sometimes there’s swelling, drainage, or even ...