There can be reasons like vasovagal syncope, or other reasons - so since the causes for blackout can vary and I am not a medical professional, just a patient like most that post here, I am just not in a position to do much else than help support and sympathize at this point. No one can diagnose over the internet and a lot more data would be needed by the doctor anyway.
The doc is sending her to a cardiologist for a reason - those cardiac possibilities have to be ruled out as well.
also Her stress was a personal stress which hshe experience more frequent blackout episodes but as her stress is gone the frequency of the blackout has decreased the only possible symptom i have came across is synocope or hypotension which is still kind of vague but since there are lot of possibilities can this be more relatedsome kind of a cardiac issue?
HI rumpled when my sister use to experience it more frequently she was under alot of stress and ever since her stress has gone down the frequency of the blackouts have gone down but its still happening so can it be relator to strss or tension? i kno i have looked up her blackout symptom to the brain tumr and it does not match to any of the sympotms for the brain tumor so my guess the brain tumor symptom is less likely?
So the doctor is doing the right thing - he is checking her out for any cardiac issues (which is possible) and any possible lesions.
It is not a specific symptom but obviously not a good one. The EEG is to check for epilepsy or stroke activity.
Until you get any testing back, it will be hard to tell - but keep us posted!
and on top of that i forgot to mention the neurologist is sending her to have a brain mri ct scan of the mri EEG and to see a cardiologist