I wrote this and realised no one would ever read to the end, so I'm starting with a list of symptoms that have been attributed to the problem in my parathyroid glands (NOT thyroid).
Symptoms:
Extreme exhaustion
Foggy brain/wondering about dementia
Bone pain
Joint pain
Waking up "stiff" and
Feet hurt when you first start walking
Burning sensation patch on foot
Cracking headaches
Feeling incredibly weak/
drained
Restless sleep/ Insomnia/nightmares
Depression, anxiety, very bleak thoughts
Forgetfulness/ cognitive problems
Constipation
Nausea/ heartburn
Sweating at night
I didn't have them all at once, and it's only with hindsight that I can make the list. Some of it is very every day, but I've never had heartburn in my life, or constipation!
I'm a little spooked this week because I've started seeing "things" out of the corner of my eye.. I'm left wondering if there was a mouse, or a spider, or one of the kids and I just saw a corner of something moving, black and hazy. I have been reassured, oh that! That's just the hyperparathyroidism! Hallucinating...
Good news, the second the adenoma is removed, I will start to return to normal. So my the time I'm fully out of the anaesthetic, I should be "well" again.
Back to the beginning in case it's helpful.
I went through the menopause early, several years ago, and thought I had more or less got it all under control.
I started to get a long list of vague symptoms that kept being assigned to the menopause. I asked the GP if it's possible for HRT to just stop working, and she said it's probably just age related! 
In her defence, she has always been amazing, and sorted out testosterone for me and all sorts.
But even more reason for me to thing this was my new normal, even though I'd been completely fine for a while.
Late last year, I was assessed for diabetes, as I was very thirsty, constantly peeing, and bad headaches.
Again, very fortunate that the doctor I saw was not convinced that it could be explained by the beginnings of t2 diabetes. I also told him everything else I'd been experiencing.
One of the blood tests that came back was for the hormones produced by the parathyroid glands.
It was out of range, too high. This doctor said it was probably worth watching, but unless I had osteoporosis or kidney stones, we could just watch and wait (can I say my second wtaf at this point?).
Given that I'd already had bone density issues for years, I thought I'd do some digging.
It turns out there's only really ever one reason for a high pth result, a benign tumour that causes your hormones to go haywire, and demands calcium from the bones goes into the blood.
Over the last 3 months I've finally had some scans (which only help about 70-80% of the time), and one did show a tumour. So I'm having surgery in a couple of weeks.
If you ask an endocrine surgeon they will always say it should come out. They would, they're all about the slice and dice. But now I know what I know, I would agree.
Oh, and apparently this first came up 6 years ago, but wasn't important because my calcium levels were fine. Except that it doesn't need to be high either. If you drink a lot of water, and don't consume a lot of calcium, it may not show up.
If you've got this far, thank you.
It's not very common, but I suspect it would be more common if it was checked iyswim.
If ANY of this rings a bell, whatever your age, ask for a blood test
Seriously, one blood test. They'll probably be testing iron etc anyway.