Ironic -- had to do that today.
I have reflux pretty bad, control it with OTC stuff; the past 6 months have seen some real 'failures' with the medication. Last night was one of those, and as a result -- in addition to nasal congestion and mild nausea, I had an onset of reflux that woke up after 2 hours' sleep, and kept me up the rest of the night.
The ride to work was fairly normal, but arriving at work was about the time it really started to hit me. Turns out, I lasted about 2 hours, and just had to leave early. My commute home was twice as long as usual, timewise. Had to downshift, legs weren't there.
Not sure yet if I'm going in or calling on tomorrow.