###Human: I am having severe headache. I am having teeth clattering with cramps all over the body. Why is this happening? ###Assistant: Hi. Please get the following investigations done: There can be various causes which need to be ruled out. It can be a deficiency of vitamin B12 or calcium which is a very common cause for such a problem. Get CT head to rule out any brain-related problems. Follow these instructions as of now: Revert back with the reports to a general medicine physician online for further follow up -->