My hand is shiviring in a noticable way ?

I was setting today having lunch, and i had my elbow on the table watching tv, while i was holding the sandwich i noticed that my hand is shiviring in a noticable way, i can feel it moving,I put my sandwich down i held my hand infront of me , nothing no shivers, this happens on and off for sometimes, iam already running thru exams and iam ver stressed out, is this from the stress or is it something else? It got me all worried ??