What can cause hands to shake?

Dear Ask The Doctor: I noticed that my Mom's hands are starting to shake slightly, from time to time. She is 78. I don't want to ask her about this to upset her, in case this is normal and nothing to worry about. But I wanted to see if this could possibly be something that she should ask her doctor about. If so...I will point this out to my Mom so we can have it checked out by her physician. Thank you for your thoughts!

Dear Loree: It is not unusual that the elders experience slightly tremors in the hands (senile tremors), there is other causes of tremors like:  Essential Tremor which usually begins in one upper extremity and soon affects the other. Essential tremor rarely extends from the upper extremity to the ipsilateral leg. Tremor may be intermittent initially, emerging only during periods of emotional activation. Over time the tremor becomes persistent. A degree of voluntary control is typical, and the tremor may be suppressed by skilled manual tasks and during sleep. Other causes include: Parkinson, in which the tremor is the most common initial symptom, occurring in approximately 70% of patients. It is described by patients as shakiness or nervousness. It may differ considerably, showing up only with stress, anxiety, or fatigue or it may occur only when supporting weight with the affected limb, such as experiencing arm tremor when getting out of a low chair. But along with the tremor, Parkinson’s disease have other criteria to be diagnose as: slow movements, stiffness or rigidity, depression, slowness in thinking and speaking and a general feeling of weakness.