I had acupuncture a couple of years ago and that fleshy bit on the base of the thumb is where he always stuck the first needles - a good place for stimulating natural endorphins apparently. And it's probably not unconnected that when we're a bit wound up we tend to 'wring' our hands and unconsciously put pressure on that area.
Mary, just the thought of the peppermint of lavender is helping! And as I'm on my own I can go and try the various massage ideas without raising anybody else's eyebrows!