CAUTION: Some of the pictures in the following pages (Problem Piercings) are not pretty/may disturb. They are for educational purposes, as an example ONLY.
Please seek a piercers advice before diagnosing yourself.

If you fail to change a piece of jewelry that is too short, a possible result is embedding. Prevention is the best way to avoid this from happening. If your piercing jewelry is starting to sink into your skin/tissue, see your piercer right away for a longer bar. 

Some piercing do embed slightly, we refer to this as 'nesting'. Lip and tongue piercings tend to do this as our oral tissue is very soft. There is a major difference between these kinds of embeddings. If more than half a ball has disappeared or the skin seems to be growing over your jewelry, visit your piercer as soon as possible. Oral tissue regenerates much quicker than other body tissue. Embedding overnight is highly possible. 

If you cannot reach your piercer anytime soon, there are a few things you can do to help minimize the embedding/swelling. Resting, ice and anti-inflammatory medication from a pharmacy or supermarket can greatly help until you can get the piercing changed.

In the event that the tissue completely grows over your jewelry, and neither you or your piercer can push it out to the surface. You will need to seek medical assistance.