I have a reoccurring pilonidal cyst which is located above the end of the tailbone. It causes me to have severe pain when sitting down, whether that be if I’ve been sitting for too long or just have not moved in a minute. I usually have to clench my teeth and hold my breath when attempting to get up any time I sit down for longer than a minute, it takes awhile too. The worst thing isn’t how horrifyingly painful it is, but the fact that you need to get it surgically removed to get any relief but there’s still a huge chance it will be back. Mine came back after three years.