Muscle Shaking

About 3 years ago, I noticed that sometimes my hands, arms, or legs shake slightly. Also, sometimes I experience a few jerks when I go to sleep really late. However, I was also really stressed out during that time, and I atributed it to stress, and didn't think much of it. However, recently, I read a lot on muscular degenerative diseases, such as parkinson's, als, etc., i'm getting kind of paranoid. And when I think about it, the shaking is still kind of present even now. I also know that there is harmless muscle shaking, called fisciculation, which isn't really indicative of any disease. Can someone give a diagnosis/more insight into my symptoms? Also, even if it's harmless, how can I reduce muscle shaking? (exercise, nutrition etc.)