I have anxiety to the extent that when i have to spoke in front of people, my heart beats to an extent that i can hear? what's the cause of this?

Anxiety: Some polls have shown that speaking in public is one of the most stressful chore for a high % of people. This is from your adrenaline which may at times works to your advantage in a speech if controlled properly. For some cases,a beta blocker type of medication may be necessary. In general, if you know your subject well, you should feel more assured of yourself and less anxious about it.

Panic: A beta blocker med is usually very effective if used an hour or so before a performance. Sometimes a tranquilizer is also useful.