It has been postulated that hair penetrates into the subcutaneous tissues through dilated hair follicles, which is thought to occur particularly in late adolescence, though follicles are not found in the walls of cysts. A sinus develops with a short tract, with a not clearly understood suction mechanism involving local anatomy, eventually leading to further penetration of the hair into the subcutaneous tissue.
Research is going on in a large scale. Many scientists have submitted their articles for pilonidal cyst.
Around 50% of population is suffering from this disease.