I developed a pilonidal cyst while in the Air Force. It's colloquially called "jeep driver's" disease. You must have the enfolding of skin at the coccyx, (tail bone) and then receive a striking blow which inflames the area. A kick in the butt!
I was very fortunate. The cyst was excised and the Air Force doctor assured me that there would be no reoccurrence of this Xlinton!
Would that the body politic were so fortunate!
I've had these cysts off and on for most of my life. They're a nuisance and sometimes require medical treatment, but they didn't keep me out of the Army.