I have had every test you can think of, including an MRI of my spine. My spine is A-okay, no discs pressing on anything. As you say, nerves cause pain on one side or the other and my pain is always in both arms. Meds such as ibuprofen do not work and I would not take anything stronger since these sessions can last for only a minute or two. Don't do well on drugs. A little bit goes a long way with me so I stay away from them.