An essential benign tremor is a neurological disorder characterized by rhythmic and uncontrollable shaking, as stated by Healthline. It affects several areas including the tongue, voice box, lips, legs and feet as well as the jaw and head. However, the most affected body parts are the hands, notes Mayo Clinic.
The exact cause of essential benign tremor is not understood, according to WebMD. Its cause is likely multifactorial, which means that several environmental and genetic factors play a role in its development. The main symptom is tremors, though patients sometimes experience abnormalities in balance and gait. The tremor worsens when the person is hungry, agitated, emotional, tired or during extreme temperatures.