When trauma responses are activated they can look different based on the individual; however, broadly, they likely include the following: intrusive thoughts, unpleasant bodily sensations, heightened emotions, hyperarousal (fight or flight). Oftentimes if trauma has been a part of your life, you may be living pretty consistently in a state of hyperarousal, which can be quite depleting on the body. You may not even know this is happening!
When trauma reminds grab hold, it can be really challenging to stay in the present moment. I know I find it to be. But staying in the present moment is precisely the antidote, at least partly, for working through trauma: because they danger is passed but your brain acts if it is current. Now this might get tricky if you’re still dealing with trauma triggers (i.e., family members who abused you, etc), ongoing relational trauma, or dealing with the effects of a history of relational trauma (i.e., inability to trust people). Your brain can use that as even more fuel to be hypervigilant. It may be near impossible to work through trauma until you are in a safe space and free from being retraumatized; however, there is a simple thing you can do in the moment when you feel flooded to try to bring yourself back– bilateral stimulation. You can cross your arms across your chest and tap your shoulders, cross your arms in front of you in your lap and tap your legs, or even go to youtube and watch an EMDR video. This is NOT meant to replace specific EMDR therapy, but simple stimulation like that forces your brain to at least partially remain in the present moment, which can help the calming process. If you feel you are able, you might also try to through in a type of affirmation such as “I am” or “will be ok.”
I myself watched this video this evening and couldn’t even get through 10 minutes of it before I felt calmer and literally bored and couldn’t continue. Actual EMDR does the eye movements in shorter segments, but using the bilateral stimulation for relaxation purposes can be a useful tool as well.