The primary symptom of essential tremor is uncontrollable shaking, usually of your hands and arms. While essential tremor impacts both sides of the body, sometimes one side might shake more. Shaking often increases during movement and can be triggered by fatigue, stress, or caffeine. Over time, you might develop additional essential tremor symptoms, including:

• Balance or walking difficulties
• Head shaking in a “yes” or “no” pattern
• Voice shaking

There are two main types of tremors:

• Action tremor: Shaking happens when you perform an action, such as picking up an object.
• Postural tremor: Tremor symptoms occur when you hold a body part in the same position for a while.

Experts don’t know what causes essential tremor, but certain factors may increase your chance of developing the condition. Risk factors for essential tremor include:

• Age: Essential tremor most often appears in people age 40 or older.
• Family history: You’re more likely to have essential tremor if one or both of your parents also has the condition. 

Your doctor may diagnose essential tremor by watching your movements during a comprehensive physical and neurological examination. Your doctor will also ask about your medical history and your family’s medical history. 

No medical tests exist to confirm essential tremor. However, your doctor may conduct tests to rule out other conditions that cause shaking. Tests include:

• Blood and urine tests, which check for signs of infections, genetic disorders, or other conditions that may be causing symptoms
• Dopamine imaging (DaTscan) to check for other conditions that may be causing symptoms
• Magnetic resonance imaging (MRI) to look at your brain tissue
• Computed tomography (CT) scan to see the structure of your brain