Pain in right shoulder & down right arm, numbness in thumb too.

Neck problem: This likely a result of the nerve that goes to your arm being pinched in your neck either by a bad disc or a muscle spasm. Ibuprofen is the first line of treatment and evaluation by your physician to make sure there is nothing else going on.

May be cervical prob: You may have a nerve problem starting in the neck (cervical region). You may also have a shoulder disorder including rotator cuff injury. You can start with your primary medical provider or with an orthopedic surgeon. Hope that helps.

Anatomy: Likely location could be neck, C-6, upper brachial plexus in shoulder, nerve compression in wrist. Imaging and EMG could confirm site of pathology with interventional treatment based upon this.