My mom fainted Wednesday and Saturday. Both times she was admitted for one night. They did MRI, MRA, EEG, checked her carotid arteries in her neck and EKG and wore a heart monitor. ALL tests showed no issues. They did find her sodium was 130 with 135 being normal and said she was dehydrated. Today, Monday, she didn't like the caregiver and was upset and had a headache I gave her daily morning meds and sent the caregiver home. I asked her to lay down. My dad has slight dementia. At 12:30 we decided to wake her she would not wake up. Went to ER. Cap scan, blood work and urinalysis. Nothing.. ER dr told me this was dementia causing this. Next time I should just keep her at home. I'm wondering if there is any test that would show anything else. Or should I just take the ER dr's advice.
If a whole team of ER Dr.'s can't figure out what's wrong with your mom, if anything, I doubt that anyone here can come up with something new (not that we're not all great) but I'm wondering if her BP is bottoming out but that would have been one of the first things the hospital would have checked. They would have checked her sitting BP and then had your mom stand and checked it again. It's a pretty standard test.
I'm also pretty sure the Dr's went over your mom's medications as well.
Having said all of this I don't think fainting in normal in anyone for any reason. Have you taken your mom to see her primary care Dr.?