What Causes Tremors In The Hands?

I have been developing shakeness in my right hand. I can still work but my writing and fine motor skills are challenging at times. My doctors has told me that unless it really affects my day to day activities he will just make note of it. Is there any test that can been done early to detect anything? Is there anything I can do to minimize the long term? I am 58 years old. Thank you. Bob