I have 10 crowns for 7 years. All of a sudden cold is excruciating. No bumping nothing unusual. What is this?

It sounds like you have decay under the crown that has made its way into the nerve. Its called irreversible pulpitis. The options would be an extraction or a root canal through the crown.

There are many reasons for sudden cold sensitivity. Without the help of xrays it will be difficult to give you an answer. I would call your dentist and schedule an appointment soo so that you don't have a larger problem over the hlidays.

Crowns are subject to wear and tear and good home care.  Teeth that are crowned can become sensitive when they were previously not..even years later. It may be due to recurrent decay ( good reason to have periodic check-ups).  Recession of the gum line exposing a sensitive area, recent trauma to a tooth or just the fact that over time a certain percentage of crowned teeth end up needing replacement and/or root canal therapy.  That timely check-up at your dentist seems to be in order...the sooner the reason is determined the quicker it can be treated before it grows more serious.

This can be due to receding gums,crowns might be ok. The only thing is that if the gum receeds there is a big chance of having the root exposed, and this will make the tooth to be sensible. Of course Xrays needs to be seen, but if it is what I think, based on your description, then you will need or either change the crowns or perform a gum technique to restore the sensitivity. I hope this helps.