Can Mattress Cause Shoulder Pain?

To clarify a bad mattress can cause shoulder pain and many other issues. With a good mattress you can avoid shoulder pain and have a deeper and better sleep on your mattress. But to answer the question yes, a mattress can cause shoulder pain. Shoulder pain caused by a mattress could be because of the mattress being too soft or too hard. If the mattress is too soft your shoulders would sink into the mattress too much putting your body in an unnatural position. If the bed is to hard it will not allow your body to sink into the mattress at all and you body will lay flat on your mattress. However, the human body is not naturally flat so having a hard mattress would just end up hurting your body instead. 

How do I get rid of shoulder pain from sleeping?

To help get rid of shoulder pain from sleeping it would help to get a new mattress. This because if your mattress is old, it is likely that the support core is either damaged or just worn out over time, so the mattress is unable to give your body any support. Another way is to get the right pillow to help to help support your shoulders and not let them lay flat on the mattress, but at a slight angle will relive some of the pressure on your shoulders.