Tremor is a rhythmic, alternating oscillatory movement caused by a repetitive pattern of muscle contraction and relaxation; it is a fine vibration sensation that is touched by the hand, and is similar to the vibration sensation touched by the neck or front chest of a cat, so it is also called “cat’s pant”. So, what are the main performance characteristics? The following are the main characteristics of tremor: 1. Frequency of tremor: The frequency of tremor in Parkinson’s disease is 4-8 times/second, which is generally slower and larger than simple tremor, and faster and smaller than the frequency and amplitude of action tremor. This feature can also help us to distinguish other diseases, such as chorea, cerebellar disorders, and hyperthyroidism. 2, the impact of tremor on movement: when the tremor is mild, it can not affect the motor function, or life can be self-care; as the disease progresses, the tremor can affect part of the motor function. For example, it is more and more difficult to write or even unable to write, and life is not self-care. 3, tremor accompanied by signs: tremor with increased muscle tone, mostly seen in Parkinson’s disease, can be found in the examination of “gear-like” straightening, in the head and neck extension and flexion and elbow, wrist joint passive activities easily found. This kind of resting tremor is not accompanied by ataxia, and the tendon reflexes may not change significantly, nor is it accompanied by pathological reflexes and sensory disorders. 4.Tremor is fluctuating: sometimes it is obvious, sometimes it is reduced or disappears. The tremor is obvious during nervousness, emotional excitement and initial movement, and it is reduced during random movement and disappears after sleep. 5.Tremor site: usually starts from the distal end of one side of the upper limb, mainly the thumb, index finger and middle finger, which shows the movement of the fingers like rolling pills or counting bills. Then it gradually extends to the ipsilateral lower limb and the contralateral limb, and in the late stage it can spread to the jaw, lips, tongue and head. In the early stage of the disease, the patient does not care much about the tremor, which often appears when the fingers or limbs are in a particular position and disappears when the position is changed. Later, the tremor develops only when the limb is at rest, for example, when watching TV or talking with others, the limb suddenly appears to tremble involuntarily, and the tremor decreases or stops when changing position or movement, so it is called resting tremor. Sometimes the lower extremities are also more pronounced or other parts of the tremor are more prominent. In some patients, the tremor appears later and is predominantly tonic, which is often misdiagnosed as hemiplegia.