Thanks for the reply.

At one time I don't run too much - say between 6-10km. I consider myself to be physically fit and am used to running, so I'd be suprised if the pains were a result of stress caused by over exertion.

I'm still trying to work our how what/when I eat affects the pains - they do get worse in the evening and when lying down. I try to eat at least 3-4 hrs before I sleep, but often will sleep more immediately after eating, but i haven't noticed much of a difference yet in terms of the pains and how soon I sleep after eating.

I do sleep prone, but recently have been having palpatations which are more noticeable when lying on my front, os have also shifted to sleeping on my side and back. Thanks for the tip on raising the head, I'll do that.

Worryingly my symptoms do seem to be getting worse, I have a permanent ache in my left arm, the left side of my face feels almost numb (although when I touch it it's fine), and I'm feeling nauseous.