I know anxiety can cause shortness of breath, tight chest/throat, shaking, hyperventilating, dizziness, and nausea. Although, all of those are usually caused by a spike in anxiety for borderline or full-blown panic attacks. What I'm asking now is simply, does anxiety cause physical issues such as nervous ticks or muscle spasms?

For as long as I can remember I've had nervous ticks: biting my nails, tapping my foot/leg, tapping my fingers, biting my lips, rocking when sitting still, etc. I've recently tried edible medical herbs, and I've noticed when I'm in a good, really relaxed state, my body just jumps around. I have muscular spasms all the time when I'm under the influence of MJ! And I am by no means a frequent user, either. Once every four or five months is about as often as I do. Since my recent use (last month), and my experience with the same issue, I've slowly been paying more attention to my body and the fact that I have these muscle spasms without being under the influence also.

Is this something that can be caused by the anxiety disorder? Is it possible there's something like "too much brain activity sending too many signals even when they're not supposed to" sort of thing going on?