Tremors At 18?

Hi, Im pretty new here and have been looking around. Id like to ask one question. When I hold my hands out I shake alot, Im not ever nervous its just constant shuddering. I asked one of my doctors and he told me it was called tremors, which is commonly seen in elderly people. Id just like to know what it is and how to calm my "shakes". Especially since in the future Im going to be a nurse and I dont want to shudder when Im inserting a needle or doing something more important.