A stiff neck is an acute strain of the neck muscles, characterized by pain and restricted mobility. While it is often attributed to poor sleeping posture or an unsuitable pillow, the underlying cause is more commonly excessive tension in the nerves and muscles of the neck and shoulders.
During sleep, blood flow and heart rate naturally decrease, which can further restrict circulation in areas with preexisting poor blood flow. This can result in muscle tension in the neck and reduced joint mobility. Over time, having a persistent stiff neck may compromise the health of the intervertebral discs.





