Autism

My (unscientific and possibly completely wrong) theory is that the long term pains can become relatively unnoticed background noise such that we don't realize that we are expending some amount of energy on mental mitigation for those pains. Especially if we also have a general lack of bodily awareness already, which is apparently common among us autistic individuals.

When we are closer to burnout though, all of those small expenditures are so much harder because we don't have as much energy overhead in those times, making every internal and external demand feel much more taxing.

Yep, I suffer this. It's annoying. Like, I already have a short temper, why does it have to get worse?

Limited knowledge man here so here a little google

Endorphins are the body's natural painkillers. Endorphins are released by the hypothalamus and pituitary gland in response to pain or stress, this group of peptide hormones both relieves pain and creates a general feeling of well-being.

Link:

https://www.health.harvard.edu/mind-and-mood/endorphins-the-brains-natural-pain-reliever#:~:text=Endorphins%20are%20the%20body's%20natural,general%20feeling%20of%20well%2Dbeing.

My anecdotal experience is that my pain threshold is much higher when I'm in a particularly critical phase of my depression