Most of the time after sitting or lying down for a little while, when I stand up I feel very weak as if I might fall. I tried to do research on it but I can't figure it out, I have yet to fall but I've gotten close. Anyone know what could be wrong?
Edit:
Thank you everyone for replying so quickly on this, and I'd like to state something that I didn't mention.
1. I recently went to my doctor and she said my blood pressure was healthy (we went for a different reason, we thought my appendix was going to burst, gladly, it was something else)
2. I'm very young, so if there's more common in my age range according to my symptoms, please let me know!! (Age Range: Middle/High School) (Gender: Female)
3. It's no longer when I just stand up, it's now a constant feeling.
It fees like... I've been running for an extended period of time and have yet to stop.
4. I do not take any medications.