I feel light pain on my chest for around 20 secs and vanishes. i have felt this many times in last three months. any cause of concern ? pl. advise.

Yes..Go: Always pay attention to chest pain...If it is cardiac, it needs immediate attention, and the only way to determine this is to have an evaluation by a doc...It will also put your mind at ease if you find out it is just something temporary, simple, and easily treated or explained...Get it looked at....Don't take a chance on being one of the many who "die from denial".