Stand up too fast or move head fast and get lightheaded. what is this a symptom of?

Several potentials: Can be associated with drops in blood pressure, secondary to medications or due to dehydration or dysautonomia issues. Anemia can cause this, and low thyroid function may also contribute. A large number of pts. With migraine headaches also report this symptom. Inner ear issues may be another possibility. Best to have a physician do an exam to pinpoint the problem.

Positional vertigo: The loops of balance have fluid,(in the inner ears)if there is sudden changes in pressure within these canals,but more likely the crystals,get loose,these float and cause your symptoms,if the condition is prolonged,consider Ent evaluation for appleys treatment.