How come my teeth are chattering when my more terrible pain comes on??

Normal reaction: When cold, Anxious or in pain brain sends a message to the muscles to twitch. It is normal reaction when stimulus is there. If chattering happens when there is no stimulus or last long after the pain or anxiety is gone it might be a neurological issues and a consultation is needed

Its very common: for muscles all over your body to "shiver" and teeth chatter while you are in severe pain. See your PCP for diagnosis and pain management.

Signal: It's a signal from your body that it's under severe stress. Your body is telling you to get help. Make an appointment with your GP to determine the other red flag that's being waved, your "more terrible pain."