Hi, i've just noticed a small hole at the top of the cleft of my bum cheeks. it's not sore or causing me problems but now i'm v worried?

A little cyst?: A pilonidal sinus is a small hole, that may lead to a tiny tunnel, in the skin. It is usually at the cleft of the buttocks where they separate at the top. Showering each day helps keep the area clean, but there is nothing else to do for it unless the pilonidal sinus becomes infected. Then, it is treated with antibiotics and sometimes needs surgery to remove a cyst that has formed under the hole.

You need an exam!: Obviously, you should go to your primary physician and get an examination as soon as possible but I doubt you need to go to the ER. I doubt you have cancer. You may have a pilonidal cyst or fistula but again, you need to be examined to find out what you have. If you don't have a primary physician, you can ask for one through your health insurance company or local medical society.