I seem to have developed a sleep disorder. To be exact, I've been tested for sleep apnea - for those of you who haven't met this personally, you quit breathing for various (brief) durations during sleep, and then start again with a gasp. You don't usually wake up, although you may wake your bedmate up, as this is often associated with snoring. It does interrupt your sleep; you don't always realize it.
The day-to-day effect of this is that you're tired, all the time; you never feel as though you've had enough sleep. A secondary side effect, for me, is that I get uncontrollable urges to fall asleep whenever I'm mildly (or more) bored. Falling asleep in meetings is merely embarrassing. Falling asleep at the wheel while commuting to work is potentially fatal. I spent several months literally fighting to stay awake at the wheel, fortunately never coming to grief. But it's a very unpleasant feeling.
Then I had to attend a meeting in San Francisco (driving was completely out of the question; do you know how much parking costs there??), and discovered by accident that my exercise program has brought me back to the point that I can walk to the BART station in under 20 minutes. (Not much under...) This is the breakeven point that says, hey, you can ride the train to work, and you get another 40 minutes a day to read the paper. Also, with the new in-ear earphones I got, I can listen to my iPod on BART. The downside is an extra half hour of commute every day (15 minutes at each end).
But I was still tired all the time, so I sent my doctor an email (thank you, Kaiser, for secure email) asking, why am I so tired all the time, when all the blood tests come back normal? And my doctor said, have you been having trouble sleeping? Has your partner noticed anything? So, I asked my husband, and he said, "Oh, yeah, you have sleep apnea; I've had to shake you a couple of times." (He claims he told me this, but if he did, I don't remember...)
I reported this to the doc, and the next thing I know I have an appointment to be tested. Being tested entails wearing a small computer unit on your arm all night (as the nurse said, we don't care if you sleep all night or not but we insist you wear the box for at least 8 hours), hooked up to an oximeter on one finger and a blood pressure cuff on another. This wasn't especially easy to get used to, and the day after I was even more tired, but I caught up the next night.
I haven't heard the test results; this isn't like blood tests where you get an email sometimes the same day. But depending on the results, I may have to learn to sleep with a mask on - attached to a CPAP machine. (Google it; there are lots of sites.) The best of these masks looks like a dust mask; the worst looks like a full-face gas mask; and it's attached by a hose to a machine on the night stand. And they're all kept on with a sort of harness of straps. They don't look at all comfortable to sleep in; but I'm told the result is worth it. I'm hoping this will all just go away.