Feeling everything

I occasionally get this. It’s to do with the autonomic nervous system. https://www.msdmanuals.com/en-gb/home/brain,-spinal-cord,-and-nerve-disorders/autonomic-nervous-system-disorders/overview-of-the-autonomic-nervous-system

I have found that I can control it by abdominal breathing and meditation. There are a number of videos on the web that will explain abdominal breathing.

A visit to the GP may offer an alternative solution and at least give you some reassurance.

It is probably wise to have a chat with his GP about this BUT this could be something to do with a sensory processing phenomenon known as Interoception

www.google.com/.../interoception-and-sensory-processing-issues-what-you-need-to-know

It might be worth taking him to a doctor to put all of your minds at ease.

With autism, our internal wiring is a bit different and it may be that his proprioception has gone a bit askew. Has he been under particular stress recently or particularly anxious in the days/weeks prior to this episode? This could have caused his senses (nervous system) to become overly heightened/sensitised so he's experiencing sensations he shouldn't. Also, does he have a special interest in biology/anatomy etc? It may be if he has been reading a lot about internal processes that he is now in some way experiencing them psychosomatically.

I'm not in any way medically-qualified or experienced to answer this, but there are auties on here with synaesthesia and they might be better placed to advise.