What is hand tremor? Hand tremor is an involuntary muscle movement, trembling, or shaking of the hands. Tremor most accurately refers to a small, rhythmic shaking movement that occurs in a back-and-forth pattern. Everyone has a small, sometimes undetectable, shake when they move their hands. Fatigue, stress, feelings of anger or fear, caffeine, and smoking can make this normal shaking more prominent. Hand tremor can occur at any age but most commonly occurs in middle-aged and older men and women. Types of tremors Tremors can be classified as rest or action tremors. Rest tremors are movements that occur while your body is at rest, such as when your hands shake while they are supported on your lap. The extent of the tremor increases during mental stress. Rest tremor is characteristic of Parkinson’s disease. Action tremors are movements that occur when your hand is performing a voluntary action, such as gripping a fork or signing your name. Action tremors can be further classified as postural, isometric, and kinetic tremors based on the specific movements or tasks that trigger the tremor. Action tremor symptoms are characteristic of a variety of diseases, disorders, and conditions, including essential tremor, drug withdrawal, stroke, brain tumor, and multiple sclerosis. Short-term tremors that disappear quickly can be due to an anxiety attack or stress; whereas, chronic tremors that come and go over a longer period of time can be due to essential tremor. Any type of hand tremor, even if it is temporary, needs to be evaluated by a medical professional. Hand tremor can be due to serious, ongoing diseases, such as Parkinson’s disease and multiple sclerosis. In particular, a hand tremor on one side of the body can be indicative of brain damage from a tumor or stroke. Seek prompt medical care if you, or someone you are with, have symptoms of tremor.