My mother is 80yrs old. she has bad nerve pain in legs, burning feeling in legs. hard to sleep at night. doctors so far dont know whats wrong. any over-the-counter pills you can recommend?

Surely, you might consider tylenol, but the real question is the etiology of the burning pain in the legs, and you do need to get an experienced neurologist involved. She could very well have a peripheral neuropathy of the small fiber type, and this could be readily diagnosed by a 3 site skin punch biopsy. This should be confirmed with the appropriate interventions.

Peripheral neuritis, peripheral vessels atherosclerosis may be a cause. She is 80 yrs old. Does she have diabetes?