Pain in the neck, back of the neck, head, left shoulder, elbow and numbness. What is causing my pain?

The numbness is probably explained by a nerve is irritated or rubbed by other structures in the neck. A herniated disc can press the adjacent nerve roots that supply the shoulder and arm. If it is degenerative arthritis, then the bones soften around nerves or pinched, causing similar symptoms. This pain and numbness should be evaluated by a doctor. If you are experiencing weakness, then this is more urgent and should not delay seeking treatment. You may be given medication, physical therapy, steroid injections, an MRI of the neck and then go to a specialist for further evaluation.