Does your heart beat fast when you are around a person you have a crush on?

It beats faster because it is your first time loving and you get this slight gut ake feeling,and the person might be fo you.

Alternative answer: You may be familiar with the "fight or flight" mechanism, that is, when you are afraid your body gets ready to either defend itself or run away. This is stimulated by the hormone adrenaline which is produced when you are afraid or stressed. This hormone is responsible for making your heart beat faster, speeding up your breathing (to give extra oxygen to your muscles) and diverting blood from your digestive system to your muscles (for the same reason). This is the reason why you may also experience "butterflies" in your stomach.

Ok, back to your question: When you are in love, seeing that person can make you nervous. This activates the production of adrenaline which then makes your heart beat faster.