I was just reading through some other threads and came across a post where another user emphatically claimed a connection between "a very hard knot on one side of the neck" and CH.
I didn't think much of it at first, but ended up feeling around my neck anyway, and sure enough, on the left side (same as my usual CH pain), the muscle seems much harder and has virtually no "give," as compared to the right side.
It's not easy to explain as I don't know anything about the relevant muscles or bones, but this is on the back of my neck, close to the spine. On the right (normal) side, the muscle is soft enough that if I push enough, (I think) I can feel down to the vertebrae, and feel a small amount of corresponding pain there. But on the left I can only push against the muscle, never feeling anything resembling bone, and never eliciting any pain.
Anyway, I hadn't seen this discussed at length outside that one mention, so I thought it might be worth seeing if anyone else has noticed this, or any connection between it and the headaches?
I'm currently in between bust #2 and #3, and it seems to be very effective already, so unfortunately (ha!) I don't think I will be able to determine anything useful by direct experimentation, at least this time. But I thought it might still be worthwhile, to see what others think.
And come to think of it, I did coincidentally happen to have some massages before/during some past cycles that never ended up materializing. I had attributed this entirely to other factors, but now, I'm starting to wonder...