Pain in upper back, shoulder, neck down arm to elbow on left side hurts the most when turning head to the right. Been 4 days. What can I do?

This sounds. like RADICULOPATHY (Pinched nerve between the 6th and 7th neck vertebrae. (see illustration) Try applying heat/ice to the back of your neck! If you sleep with many pillows try reducing them or sleeping flat> If the above measures do not help..a visit with a hands on exam to your PCP who may want to refer you to an ORTHOPEDIC or SPINE specialist is indicated Hope this helps Dr Z.