My 70 year old mother has fainted twice in the past 3 months after a lifetime without random loss of consciencness. Both times she said she suddenly felt very hot before she passed out. The first time she said she dreamed of two men arguing during the 30 or so seconds that she was unconscious. She was nauseated and exhausted after the first time this happened but the didn’t say if she felt this way on the second occurence.
She is on medication for high blood pressure and in recent years has taken high doses of aspirin for arthritis. There are probably some other medications but I don’t know all the details. She is going to see a doctor tomrrow.
I assume you’re wondering about possible causes. The list of diagnostic candidates is long, but can be divided as follows:
Fainting due to:
low blood pressure from drugs (esp. BP meds), lack of intake of fluid, blood loss, . . .
low blood pressure from malfunction of the nerves controlling blood pressure (not too rare in diabetes and Parkinson’s Disease)
low BP from heart rate too slow (or stopped!)
low BP from heart rate too fast
“vasovagal” faint (the classic one seen in movies and TV)
seizures (can mimic a faint)
stroke or warning stroke (actually quite uncommon)
a whole list of miscellaneous causes, running gamut from low sugar to massive blood clot in lungs.
The doctor’s history and physical can make the diagnosis in about 45% of cases. Investigations such as ECHO and heart rhythm monitoring can make the diagnosis in another 5%. So, in about half, no cause is identified.
I had similar symptoms fairly recently so I did some reading up on it. Of course this is purely anecdotal but Postprandial Hypotension seemed to fit my symptoms fairly closely.
If you mother suffered her attacks after eating a meal it might be worth considering.
All causes for loss of consciousness run the gamut from metabolic (low blood sugar; medications, e.g) to pulmonary (loss of oxygenation, or in the case of big blood clot, loss of perfusion on the right leading to an overall drop in blood pressure) to perfusion (loss of blood supply to the brain) to primary brain problems (seizures…strokes…).
An episodic loss of consciousness with sudden onset and rapid recovery (fainting, or syncope) is more likely to be cardiovascular than neurologic and not at all likely to be metabolic. If, for instance, a seizure is generalized enough to cause complete loss of consciousness, the recovery period is more prolonged–minutes to hours, say.
Evaluation of syncope in the elderly, particularly if there is no history of that, typically includes a workup for cardiac arrythmias and cardiac valvular disease. The primary focus is looking for a cause for a decrease in the perfusion of the brain. This is usually an overall drop in blood pressure, but can, for instance, be just a drop in the perfusion of the arteries that supply the base of the brain. In particular, various heart blocks and aortic stenosis are commonly-identified causes–when, as Karl Gauss points out–anything is found.
If nothing cardiac is found, and there’s no evidence the general blood pressure is bouncing around, the cause can be difficult to find.
Google “syncope in the elderly” and you should find lots of links.