Among the general public who are aware of Parkinson’s disease, the first thing that comes to mind when you notice shaking in the limbs is whether you have Parkinson’s disease. In medical terminology, tremors in the limbs are called “tremors”. Almost everyone has had tremors at some point in their lives. Many people tremble when they are nervous, tremble when they lose their temper, and tremble when they are tired. From different perspectives, tremors can be divided into many types, such as the often mentioned physiological and pathological tremors, postural and resting tremors. Physiological tremor: It can be seen in certain intensive states, such as anxiety, tension and fatigue; it is generally 8-12 times per minute (8-12 HZ) and usually does not affect daily life. Pathological tremor: It refers to tremor that occurs in certain disease states, such as primary tremor, hyperthyroidism, cerebellar diseases and Parkinson’s disease. Postural tremor: It is a tremor that occurs when the limb is in a position to resist geocentric gravity, such as raising the hand, standing, or performing habitual movements (e.g., pinching vegetables, writing, playing the piano, etc.), and generally disappears with relaxed emotion and active control. Resting tremor: It is a tremor that occurs when the limb is completely relaxed and not affected by geocentric gravity, and often cannot be controlled by self-will. Tremor is present in about 15% of the population, but only a relatively small percentage of Parkinson’s patients. Primary tremor is a common cause of pathological tremor, which is mainly manifested as postural tremor, often appearing when doing fine movements (e.g., when clamping dishes, pouring tea, standing for too long, etc.), and is easily affected by tension and exertion. Severe cases will shake as soon as they hold something, and the closer they get to the target, the more they shake. Calming emotions and active conscious control can improve the symptoms to a certain extent. It tends to be more common in women and usually has a positive family history. Primary tremor progressively worsens with time and age, and once present is present throughout life, but does not affect life expectancy, and may affect life in severe cases. It usually does not require treatment, and medication or surgery may be considered for those with life-limiting effects. Current research suggests that it is primarily related to genetic variants and cerebellar dysfunction. Tremor occurs in more than 75% of patients with Parkinson’s disease, but is mainly characterized by involuntary, resting and continuous movements that are not controlled by voluntary consciousness. In the early stage, the amplitude is small or intermittent, and the frequency is slightly slow, generally shaking 5-7 times per minute; hand tremor can be manifested as pill-rolling-like movements, and the tremor decreases or disappears when the limb changes position or does the action, and can be aggravated when emotionally excited; it often develops gradually from one limb to other limbs on the same or opposite side. A significant number of patients with Parkinson’s disease may have a combination of postural and resting tremor.