The pain in your neck that occurs during the morning may be the result of what you’re doing when you’re sleeping. Consider things such as an unsuitable mattress for sleeping or a mattress that has an incline in the middle. Eight hours of your neck bent at an awkward angle can cause stiffness in the joints and muscle pain when you wake up. This is also true for sofa sleepers and people who use a couch or who sleep in a small portion.