I've had problems with vertigo the last 4 days, i went to the doctor today and they said my blood pressure is low (100/65). could this be the cause?

Your blood pressure: ...is normal. However, an acute drop from a much higher pressure reading, or a condition (brain, inner ear, autonomic neuropathy, etc.) that may be entirely unrelated to hypertension control, can be at issue and deserves prompt medical evaluation please.

Need more history: Lightheadedness can be caused by lower blood pressure, but not vertigo.