Should I be worried about frequent fainting episodes?
I am a 25 y.o female, and have been experiencing frequent fainting episodes since I was 14. Previous blood tests and MRI screening have all been normal. A health screening also didn't find any problems with my heart. Just yesterday, I experienced another fainting episode (vomit, cold sweat, blackout vision) while having a haircut (seated down) and prior to that, I had H2O and sweets (was already feeling a little weak, so I tried to drink more water to help). I'm wondering if I should be taking any supplements or whether there are any other solutions to reduce the frequency of fainting? Or is this actually normal and I'm overthinking? :\
I am sorry to hear of your symptoms.
Fainting as you have found out by now has many causes though the vast majority are benign. But, it appears that you have already had a thorough clinical examination and investigations as you list MRI and heart screening amongst them.
However it would be useful to know whether the MRI was of the heart or brain and whether ECG, Echocardiography, Holter, exercise stress test and Tilt table test were part of the tests.
Your family history is also important.
If these tests were indeed perfomed and were normal, the most likely cause is Vaso-vagal syncope or VVS, which usually occurs in young adults and has "autonomic" features such as vomiting, sweating and greying of vision etc.
You appear to have had some warning and took the appropriate corrective steps such as drinking water and sweets. I would suggest that you may want to revisit the physician who performed your health screening earlier.
If the episodes are fairly frequent and disrupting your quality of life medication maybe required occasionally.
Hope this helps!