Again, not an expert, but I would guess that in a “good” comprehensive disability insurance policy, chronic pain or brain fog is not an excluded condition, per

Again, not an expert, but I would guess that in a “good” comprehensive disability insurance policy, chronic pain or brain fog is not an excluded condition, per se. It may be much harder to get the insurance company to accept your claim, but that is an issue of proof, not contractual exclusion. I would also guess that a good attorney could help make your claim succeed, even if initially denied, if it can be shown through the totality of the circumstances, e.g. a long history of doctors appointments, pain pills, attempts and inability to keep working due to the pain, a decrease in normal life activities (e.g. you used to be an avid sportsman and have clearly ceased all those activities), etc. If you claim your pain is horrible but they catch you skiing on vacation in Italy, even if somehow that was during a lull in your pain, that’s probably going to not help your claim.