I think I have cognitive impairment but don't want it on my medical record. How can I tell?

Take free online tes. Go online & search for "free cognitive testing" or some variation. Take as many tests as you can and see how you score. If you well on all of them, then it's less likely but not impossible to have cognitive impairment. But if you don't do so well on most, then you really ought to chat, perhaps off-the-record, w/your doc and start some evaluation. At least improve your nutrition & exercise.