Why do my shoulder muscles stiffen only at night?

it feels like they are sleep and im paralyzed, but only when i awaken.
Answer:
My first guess would be your pillow. You may not be getting the support you need at night and possibly your nerves %26 blood vessels that come from your neck area are being impenged. [a chiropractor may be able to recommend a good pillow, I've heard that down pillows help]My next guess would be arthritis in the lower cervical neck or upper thoracic spine. Arthritis is most noticeable in the morning then symptoms tend to subside as the day progresses.Finally, you may simply be stressed and your body is responding to it this way.

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You could be pulling a muscle during the day from carrying a too big of purse or booksack.You could be laying too much on that side.

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Too many push-ups before you fall asleep. :)
Most likely due to sleep position and/ what you are sleeping on pillow/matress/floor/ground etc.

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