I did worry a bit during a ayahuasca experience once, because I could see my hands trembling. Not out of control, but they generally don't and as the effects were increasing in intensity, I was trying my best to think about what it could mean (distant memories suggested it might be linked to hypertension).. this got me worried, so I tried to google "harmala hypertension", but as soon as the laptop screen became visible (light), it began to fold in on itself.

Being my 1st experiment with aya/dmt, I was like WTF.. ok, so that won't work. Consider that this was a solo dream at home; fortunately I was sober enough still to realize that fretting about it wouldn't do me any good. There was no one (who would understand/not freak out) to call either, so I resolved to just accept whatever came of it.

I sympathize with your feelings on this, as I too have the tendency to make it worse by starting to think about all the possible (negative) scenarios. This only feeds the fear and makes whatever you dread real - altough I know this, during the experience I find it easy to forget, especially on higher doses.

To finish, I also felt some pressure (chest, mostly) but I'd read this is normal and nothing to worry about. And during the initial nausea (later coupled with the hand tremors) the thought that I'd poisoned myself also occured.

Seems to me that this is where a meditation practice may be very useful - it would be great to be able to observe the changes in perception happening from a detached point of view, instead of identifying and identifying with all the worrying thoughts, forgetting why one's doing this in the first place.

Good report, by the way. I was hooked the whole time. Glad everything turned out alright for you.