I have had this. I don’t think it is from the heart, which you should have checked out just in case. I also have it mostly at night although not as frequently now. It’s almost like anxiety or panic yet I don’t feel those things. Possibly something with fight or flight response of the autonomic nervous system. The amygdala controls this.
Some say retraining brain (like DNRS) can help with this.
I also have chemical sensitivities. My mattress actually exacerbated all my neuro issues.
Post Edited (k07) : 9/24/2018 7:51:16 AM (GMT-6)