Essential tremor is an involuntary, rhythmic oscillation of a part of the body. Essential tremor is the most common clinical movement disorder, the typical manifestation is hand and forearm action tremor, postural tremor is caused by arm and other movements and continuous anti-gravity posture, there may be involuntary head swing, can be hereditary, senile or unexplained. 
How essential tremor is staged
Grade: Very slight tremor (not easy to spot).
Grade: easily detectable amplitude, less than 2 cm, no disabling tremor.
Grade: pronounced amplitude, 2 4 cm, partially disabling tremor.
Grade: severe amplitude, more than 4 cm, disabling tremor.
For patients, these classifications mean different levels of disease severity and different outcomes.
Where essential tremor can be affected
The disease can accumulate anywhere in the body. It mainly accumulates in both arms and hands, but also progresses upward to the head, face, tongue, and jaw, and rarely affects the trunk and bilateral lower limbs.
How essential tremor is diagnosed
Doctors diagnose essential tremor based on history, clinical symptoms, signs, alleviating triggers, and ancillary tests. The specific diagnosis is based on the following:
1.There is a pronounced and persistent tremor in the hands and forearms, manifested as postural tremor or action tremor.
2.Not accompanied by other neurological signs (with the exception of cogwheel phenomenon and froment sign).
3.Head tremor may be present but not dystonia.
4.The tremor lasts more than 3 years.
5.Family members have a history of essential tremor.
6.The tremor lessens after drinking.
At the same time, it is necessary to exclude: tremor caused by other diseases, drug-induced factors, history of neurological trauma, psychogenic (psychogenic) tremor, etc.