Why do i have muscle aches, shoulder pain, back pain, and neck pain while sleeping?

Consultation: it may be due to a pinched nerve, muscle disorders or bruxing at night. Sometimes obstructive sleep apnea can have similar effects. See your doctor for full work up

Pain: a mattress that is not firm enough , that is one that does not give uniform support to the body when one lay on it may cause back/body ache, old mattresses that let the body sinks into it also may cause body ache, specially when the pain goes away a few hours after waking up and walking around, However, it is important to rule out other possible causes of pain ,such as rheumatic diseases,