CivDiv has a great video on VA reductions, pointing out that everything you tell your VA doctor is seen and can be used by the VBA to reduce your VA rating.
(See 4 min. 30 sec. Mark.)
I went to the VA emergency room for a Service connected condition and later was using the VA website with my data, and noticed that the VBA had opened an informal claim. This was before my 20 year protection was in place. They did this in order to have me file a claim so they could order a new examination and try to reduce me.
Always stay on guard because they're lying, cheating, Little weasels, have always been and will always be.