About 10 years ago my wife was in a parking lot and was hit from behind. She didn't seem to have any injuries, but later that evening got terribly sick with headaches, couldn't keep any food down, etc.

She went to the emergency room and they couldn't find anything wrong. Eventually her headaches went away and she didn't think anything of it.

About 10 years later she had some dental work and suddenly she had terrible pain. For weeks on end. The pain radiated down her neck and into her shoulder. Her dentist said, "Oh well, I can't see anything wrong - you must need a root canal." :-( She went to another dentist, looked on the internet and decided to see an orthodontist that specialized in TMJ. He did X-rays and an MRI and was able to put his fingers in her ears and press slightly to cause the blinding pain - classic indications of a jaw alignment problem.

Her jaw was slightly dislocated in an old injury (presumably the car accident) and it seems that enough dental work was done recently to misalign the joint more and cause the terrible pain. She's been in treatment for about 3 years now (starting with a splint and then braces) and has been pain-free since that time.

The lesson - if you have any weird symptoms at all, get them checked out ASAP. Don't just shrug it off. Fixing it later is much more difficult.

Cheers,
Scott.