Nervousness before an interview is normal and even useful in small amounts, but excessive nerves can interfere with clear thinking and confident delivery.
Preparation is the most reliable antidote. Reviewing the job description, researching the company, and rehearsing key stories out loud all reduce uncertainty, which is usually the biggest driver of nerves.
On the day itself, simple physical techniques help: slow, deliberate breathing before the interview begins, arriving or logging on a few minutes early to avoid rushing, and briefly reviewing your prepared notes one last time rather than cramming new information.
If your mind goes blank during a question, it is completely acceptable to pause, say 'let me take a moment to think about that,' and gather your thoughts. A brief pause reads as thoughtful, not weak.