text: I always thought that I just had a tailbone that bruised easily until one time last spring when the pain started getting worse and it turned out that' I've always had a pilonidal cyst. I recccommend going to the doctor or the ER if you don't have a doctor. If it's a cyst and hurts that much, there's a good chance it can't drain on it's own and you'll have to have it lanced. Waiting will only make it worse.  The actual cyst is congential, but I think there are several different reasons it can become infected.