I related so much to everything you wrote. ❤️ It sounds like we share similar struggles, and as much as I hate knowing anyone else is suffering, I also appreciate knowing that I'm not alone, so thank you for that.
You had some specific questions and specific symptoms that I think are worth discussing because it sounds like you're chalking a lot of them up to autism & ADHD when they might not be.
Easiest questions first:
Does anyone else have similar experiences? ... Do others also feel this way about their body?
Yes and yes! My body is confusing af and unreliable.
Is it possible some of this is completely unrelated to neurodivergence?
Sure! These sound like symptoms of known comorbidities to me, though.
How much of this is related to general executive dysfunction that is a hallmark of autism and ADHD?
Maybe some, like
can seemingly randomly lose my coordination and take an embarrassing tumble or knock over and break things;
I do this too, maybe because I will get distracted by a thought and suddenly be less careful with my body. I stumble coming up the stairs from my basement laundry area to my living area pretty much Every Time (usually in the same area of the staircase though not the same stair) because I start thinking about what I'm gonna do when I get up there instead of "be careful on stairs" and I fumble the next step.
Maybe it's executive dysfunction, maybe it's a combination of that and EDS (more on that later)
why I can overheat and start sweating profusely so easily;
This isn't executive dysfunction. Could be EDS or something else.
why my reflexes can be so reactive and I get jumpy or overreact, like having a gag reflex that can cause me to puke or spit up over nothing;
These aren't executive dysfunction and might be unrelated – jumpiness could be PTSD, and difficulty swallowing can be PTSD, EDS, or other things.
why I can sometimes be very sensitive to pain or not feel it all;
Me too; afaik, this is a common autistic experience.
why I have IBS and other stomach issues that don't seem to correlate to any particular food or activity; why I have nerve pain in my legs and restless legs; why I can sometimes feel the constant urge to go to the bathroom or have embarrassing episodes of sexual dysfunction
These aren't executive dysfunction. They could be EDS as well.
Questions for you - do you get cut or bruised easily? Any history of sprains, strains, or dislocations? How flexible are you, relative to other people? Can you do this?
These are my actual thumbs. 👍👍 If you're easily cut or bruised and you're also more flexible than most of the people you know, you should look into EDS.
What the fuck is EDS? It is a "rare" genetic condition that causes defective collagen production, which sucks because collagen helps hold your whole self together, from muscles and ligaments to blood vessels and organs to the skin containing it all:
(screencap from link)
It's "rare" imho because it hasn't been recognized for long and because diagnosis requires getting a doctor to believe your weird symptoms could be connected and then (probably) order genetic testing ($$$). As more people learn about it, I expect it to go the way of autism and "suddenly" be much more common because more people are being tested, and someday the prevalence of EDS will be a lot more than 1 in 5000 people worldwide.
Since it's more common in AFAB folks and often comorbid with autism & ADHD, which are both underdiagnosed in the AFAB community, I kinda expect that more AFAB people getting diagnosed with autism & ADHD will result in more people in general eventually being diagnosed with EDS as they start asking questions like you're asking here, realize there might be answers, and spread the word.
I think my experience of my disability – thinking that everyone has the same problems but copes better, then realizing these difficulties aren't universal, then finding out they're connected and that group of symptoms has a name – is common, and more autistic people asking questions about these health issues they've had forever will result in more people being diagnosed with EDS and other comorbid conditions.
So, our mutual clumsiness could just be the result of inattentiveness caused by executive dysfunction, but it could be exacerbated by floppy ligaments that require extra effort to keep in place. Am I tripping as I come up the stairs only because I'm distracted, or because I'm just distracted enough to stop making that extra effort required to make my floppy ankles keep my feet up?
Here's the list of signs and symptoms of EDS from NATOpedia. I think if you skim through it with all the things you've mentioned here in mind, you'll see why I'm bringing it up.
I've got an appointment to get checked for it in a couple weeks. If that doctor dismisses my concerns, I'm gonna have a good cry and then try another. If you're also relatively flexible and fragile, maybe you should get checked, too.
Random tidbit thought:
why I have IBS and other stomach issues that don't seem to correlate to any particular food or activity
In addition to the gastrointestinal issues EDS causes, it can also cause Mast-Cell Activation Syndrome, which is basically an inappropriate allergic reaction – your body freaks out over something it shouldn't. Since stress and other environmental factors (like temperature) can affect MCAS symptoms, it is entirely believable to me that you wouldn't see a correlation to particular foods or activities; it might take the right combination of stress and other factors to set the stage, and how strongly those are affecting you might cause differences in whether certain foods affect you. (When you're at a high stress level, anything might set it off, but with lower stress it might be harder to set off.)
Of course, all your random symptoms might not be EDS and might be totally unrelated to each other. I just saw enough overlap with my own symptoms and the stuff I've been reading about EDS to be inspired to write you an essay on the subject, which I hope you found helpful. It was a good and necessary distraction for me, so thanks for the opportunity. ❤️