Primary tremor, also called idiopathic tremor, and benign tremor, is a common movement disorder characterized by postural or motor tremor of the distal upper extremities (hands and forearms) (that is, tremor that occurs when the hands are moving, or in a specific position). There may be concurrent head, orofacial, or vocal tremors, and 50% of patients have a family history. It is generally considered to be a benign, familial, monosymptomatic disorder, but it can also progress slowly. Its characteristics are as follows: (1) Age of onset: It can occur at all ages, mostly in middle-aged and older adults over 40 years of age, and some believe that adolescents are another peak of onset. Familial patients have an earlier onset than sporadic patients, mostly before the age of 20. (2) Form of tremor: 4-12 Hz postural or motor tremor is the main feature, mostly in the hands and forearms, but also involving the tongue, face, trunk, etc. There can be voice tremor, and occasionally involving the lower extremities. (3) Daily activities: such as writing, pouring water, using chopsticks, etc. can aggravate the tremor, and it is especially obvious when nervous, tired, or emotionally excited. Most patients have reduced symptoms after drinking alcohol.