A terrible crick in my neck 
I used to get those when I was side-sleeping..
What happened was, My pillow was calibrated for side-sleeping, but then that means it's a bit too high for back - sleeping. So when ever there's a switch going on during the night, it cause my neck to go out of alignment, and thus morning neck pain.
Eventually I switched to 100% backsleeping.. and lowered my pillow.. Everytime I'd turn to my side, I'd wake up, and consciously turn myself back on my back..
Over the course of several months, I was able to sleep through the night on my back, and no more neck pain, ALONG with no more lower back pain..
