What Causes Constant Shivering In Hands And Legs?

I am kunal sinha , male , age 29. I am facing a problem of shivering hands. It's not a by birth problem as it started 12-13 yrs ago. My hands shiver all the time but whenever i feel nervous,angry or excited they start shivering very rapidly. After that i can't write or hold a glass of water or even a spoon properly. Now i am feeling that this problem is not getting into my legs also. But they don't shiver all the time. I would like to know taht is their any medical treatment to cure this problem. If yes, kindly suggest me.