What worries the FAA is narcolepsy caused by sleep apnea. I have a
friend who is an absolute danger because he refuses to acknowledge his
narcolepsy, and I imagine that's not uncommon. I have two colleagues,
like me, overweight and past 50, who can only function with CPAP.
While they're not in danger of falling asleep while driving like my
other friend, they wouldnt have the energy to get through the day
otherwise.

For myself, it started when I let my regular doc talk me into a sleep
study. That produced a diagnosis of sleep apnea that I resisted.
(I'm not narcoleptic.) Nevertheless, I had to ground myself. (Per the
AOPA Website.)

To satisfy the FAA, I had to re-take not only the overnight sleep
study with all the wires, but the all-day test the following day (I
forget what it's called, maybe maintenance of wakefullness.) where
they monitor you continuously and then every couple of hours turn off
the lights and have you lie down and see if you go to sleep. (Thre's
an infrared TV camera in addition to the EEG.) Then I had to buy a
CPAP machine and use it.

What the FAA wanted was good results from the maintenance of
wakefullnes test and a letter from my regular doc that said the sleep
apnea was under control because I used the CPAP machine.

Sleep testing cost about $6000, of which my insurance paid a lot. The
CPAP machine cost less than a grand. On my second medical, I got the
doc to sign me off with a "no change," though he was reluctant and
said OK City might come back asking for more data. (They didn't.)
That suggests that you need to check around for an AME who's
comfortable with doing what mine did.

I was skeptical of the CPAP business, but after 4 years, I've found
that it does get me through the night without waking up at 4 am with
the heebie-jeebies about whatever I have hanging over my head that
day, and I actually go to sleep a little faster.

For the curious, a CPAP machine looks like a mini vacuum cleaner. Its
hose connects to either a mask that covers your nose or to what I
have, which is a snorkel-like contraption that ends in a couple of
buds that stick into your nostrils. (Not a cannula, they actually
close the nostrils.) Either way, it means the air pressure at your
nose is higher than the air pressure at your mouth, forcing you to
keep your mouth closed while you sleep and to breathe through your
nose. The result is no more snoring and none of the sudden
interruptions of breathig air that occur when your tongue or glottis
gets in the way of the air you'd be breathing through your mouth. And
those interruptions are the apneas that interupt your REM sleep, which
is what you need enough of in order to avoid narcolepsy.

For the really curious, yes you take the damned thing off for sex.

Alternative surgical approaches that don't involve CPAP include cuting
off your uvula and breaking your jaw and resetting it further forward.
I understand that some people actually opt for them. Go figure.

Don