4. Acute Torticollis:
This is a condition in which the head gets kind of stuck to one side. It typically happens overnight, so upon going to bed there is no detection of a problem, but upon waking the head is stuck in an awkward position, and painfully so.
Medical professionals suspect this is caused by small ligament sprains or muscle sprains, also overexposure to cold for extended periods of time can cause this to arise. On rare occasions, this condition may be a symptom of a larger health concern.
In which case, only your doctor can guide you in the next direction. Tumors, medication side-effects, and infections could be the more major health conners this may be indicative of. In usual cases, the condition will subside in a few days.