Acrophobia is accompanied by one or more symptoms so you just need to see if you have any of the symptoms. They are mental and physical in nature. If heights make you burst into a panic attack, you very well may have the problem.
If you sweat, have a racing heart, have high anxiety, stomach issues, or feel faint when you are up hight, you can check further into the possibilites. It is very possible if you feel this way more than one times, like every time and not one isolated instance.