When I go to any interview my heart beats more than normal and I cannot answer properly ...why?

You may be suffering from normal anxiety or an anxiety disorder. It may ve best to see a doctor about this, as it is potentially an anxiety disorder. You can see a doctor and get treatment for anxiety even when it does not classify as an entire disorder. My brother, for example, has prescribed medication against anxiety for when he has his driving test.There are different types of anxiety disorders, if you are diagnosed with one, you will be able to seek proper coping methods and medication.

There are some more instant coping methods available. You can research the Internet.