If your not a pilot this is probably not meaningful for you.
My FAA medical lapsed in 2007 and and I have not flown since. Long time followers of my blog will remember that 3 or so years ago I had a post about Sleep Apnea and getting a CPAP machine. This significantly complicates getting a flight physical. Before I figured out the sleep apnea there were some other minor medical issues due to the poor sleep that I dealt with that also complicate the flight physical. The FAA flight physical does not have a recency or last x years stipulation, the form says "have you ever".... and in today's realm of pervasive computer databases your going to get busted if you are not 100% honest about EVERYTHING!. Every yes on the form must be documented and dealt with.
The FAA Medical process as it is currently construed has a really nasty catch 22, One can fly light sport aircraft (2 seats, day vfr, gross less than 1320 lbs) with a drivers license instead of a medical, as long as you have never been denied a medical. So going to the FAA to get a 3rd class medical has risk, if you try and fail then you loose the LSA option, If you never try and never fail you keep the LSA option.
So the only way to really combat this is to gather all the necessary paperwork, all the tests reports, documentation records etc... and go individually do equivalents of all the FAA medical tests, vision, etc...so you know what the answers will be before you actually start the process.
How do you know what tests and documents will be required? You need expert advice, and while there are large companies charging thousands of $ for this help I found them to be unresponsive and bureaucratic.
(Yes I paid the initial FEE to a large aviation medical consulting co and got ZERO value for the large $) and then I found Dr Bruce Chien participating on the Pilots of America medical forum.
I contacted him directly and I could not be more pleased with the whole process. He is a AME that specializes in difficult medicals. He worked with me to identify possible issues, then gather and document these in a way that would be acceptable to the FAA. Finishing this process required that I fly to his office in Il, in the end even including airfare, hotel, rental car etc.... it was less than half the cost of going through one of the big aviation medical consulting firms.
So I now have a brand new 3rd class medical, and I'm really looking forward to flying again....