I never had such a problem until I was about 47 years-old, when I had similar events happen to me 3 or 4 times within 3 months (I remember it was only on the narrower planes.... once on a DC-9, the other times on RJ's.) It concerned me and I saw a doctor. We concluded that it was likely due to me drinking "Chinese Weight Loss Tea" that I had gotten through a mail order. I had been trying to loose a few pounds, but found it difficult with all of my business travel and professional dinners (I was Gold then, Platinum now). I saw an add for this stuff in a magazine...bought it, and was drinking it daily as instructed. It apparently had some amphetamines or something similar in the tea.

Have you recently started new medication or made major changes to your diet?