What causes a person in their early 40's to get shakes and or small tremors for no apparent reason?

Tremors and shakes: Their are many possibilities. Best thing to do is make an appointment with your doctor for an examination to find the cause. Be sure you are living a healthy life style without drugs or alcohol that could be causing you a problem.

Essential tremor: Assuming alcohol and certain medications are not involved, the essential tremors are most common. If tremors occur in resting arm and subside with use of shaky hand then parkinson's disease is more likely.