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

Also known as a pilonidal cyst, the condition forms when a sac of tissue fills with air or fluid in the crease of your buttocks. Pilonidal cyst, doctors say, is mostly caused by a skin infection.

About a month ago, I noticed I had reduced airflow in my left nostril. It never went away for three weeks so I went to the doctor. An X-ray revealed a large, smooth mass in the sinus cavity behind my ...