Quite simply, stress = cortisol = higher BG:
https://www.webmd.com/a-to-z-guides/what-is-cortisol#1
Cortisol is designed for fight-or-flight responses, flooding our bodies with the stuff we need to either fight for our lives or make a quick getaway. But prolonged stress (and pain, interestingly) will lead to constantly elevated levels of cortisol, which can (and will) cause lasting damage to our health.
It's important to not only recognise times of stress but to take measures to counteract it. These can be simple, cheap and quick, and even a few minutes of respite from your anxieties can help to make a difference and lower that cortisol level.
Everyone will respond to elevated cortisol differently, but I personally find the following tricks effective in calming myself (and therefore my BG) down:
- Just sitting outside and breathing. Not talking, not thinking, just letting my eyes drift and concentrating on breathing evenly and slowly.
- Calling a friend who knows how to listen well and cheer me up.
- Meditation (can be tricky - you need to practise regularly or it gets harder to zone out)
- Playing a game - I love MMO's for the escapism element, but I also play little card games on my Kindle before I sleep to clear my mind.
- Making a list, organising your thoughts or problems into something more manageable that you can break into actions.
- Accepting that some things are never going to change or improve, no matter how much you worry about them... and letting those things go.
- Reading / listening to troubles faced by others to keep my own issues in perspective, and offering what support and suggestions I can to feel that I'm still useful and valuable in some way (doing this one right now!).
- Asking myself "Will I remember this moment in 10 years time?" Only 3 times have I answered "Yes" to that question; if the answer is "No", it's probably something you can let go of a little bit.
Anyway, to answer your question simply: stress increases our cortisol levels, and cortisol increases the amount of glucose in our blood. To reduce your BG, you need to reduce your cortisol by reducing your anxiety.
Hope that helps,
Sock x