I suppose you could cut yourself on a fingernail if you tried but it could certainly not be done by accident.

Only as much as you could break your skin anywhere else--that is, with a great deal of difficulty and probably not by accident. Even the very thin skin of your eyelids would not be easy to break with a fingernail, and the pain would alert you long before you actually succeeded. If you're talking about separating the visible folds of skin and pushing into your abdomen, it doesn't work that way either. There is no open path into your belly from the outside--that would defeat the purpose of skin (to keep your guts in and infectious agents out). --- In response to feedback: Wikipedia's article on the umbilicus, or belly button, describes and depicts it as a scar--i.e. a patch of scar tissue, not a hole. http://en.wikipedia.org/wiki/Umbilicus Furthermore, the umbilicus is used as a puncture point for laparoscopic surgery--this creates a real and quite visible hole, which scars further and also hurts afterwards! If it were open to the inside, no puncture there would be necessary; the instruments could just be slipped through the existing opening. As for the possibility of just pushing through the skin with a fingernail, it's quite easy to provide evidence on how easy that is: try it. The pain will make you stop before you break into your own belly. If the above isn't adequate evidence, please update your comment describing what is still unclear.

yes it can, if you are overweight, mine tore open so i know from personal experience, it will start discharging very often, go to the doc asap, i waited 4 weeks and it got infected and i got real sick, go to the doc

bah humbug