Really bad head rushes when i stand up and a really bad one that felt like fainting, but was still stood up.

Patient: Ok, so I didn’t know what topic to put this under since I have no idea what it could be. Ok, so basically for the last few weeks I have been having very bad head rushes when I stand up, it makes me feel dizzy, sometimes I can’t hear for a little bit, I feel like I’m going to faint, my vision goes black and blurry for awhile. It’s not pleasant. But yesterday, I got up, and about 30 seconds after getting up my vision went black and I couldn’t see, I couldn’t hear anything except a very loud ringing in my ears, I felt extremely dizzy, I remember feeling scared and I felt like I was going to faint. When I finally snapped out of it, it took a minute to remember what had happened, but I hadn’t fainted or fallen, I was still stood up. I estimated that it lasted around 20 seconds at least, and all the other head rushes I had had only lasted around 5 seconds and my other head rushes always started as soon as I had stood up, but this particular head rush, or whatever it was, started at least 30 seconds after standing up. It didn’t feel like a head rush though, I can’t describe the feeling really, and I still feel like I can’t remember all of what happened. When I first woke up, before I remembered what had happened, it had felt unreal, like when you first wake up from fainting and your really confused and your brain is foggy. Except I was still stood up, but I was slightly hunched over. I have been on no medication, I am fit and healthy and do regular exercise. I am not old, I am a teenage girl, so it’s not like it’s age related or anything, I think. I eat healthy and I eat enough, if not too much. My bmi is in the healthy range, a bit closer to underweight then to overweight but still practically exactly in the middle. There is no history of illnesses in my faimly, so I have absolutely no idea what it is, or if I am worrying about nothing. Could you please tell me what is most likely to be wrong with me if there is something abnormal. Thanks.

Symptoms: Head rushes for around 2 months that last around 5 seconds, one really long, 20 second or more head rush that included loss of vision, loss of hearing with ringing in the ears, dizziness, scaredness, felt like I had fainted, took awhile to remember when I woke up.

Doctor: