Read through the entire BLUE BOOK before you start the application.

And, arrange an FCE ASAP to prove any limitations you're claiming. At the point I had vertigo and was stumbling and falling repeatedly during a span of 6 months, I don't think my Primary ever actually saw evidence of it, although I was sent to a specialist that documented it. (Just an example that your docs don't necessarily see everything, and while they might believe you and treat you, it's another matter for them to attest to SS about your limitations without proof.)