A 2-year-old child’s constant shaking may be caused by physiological phenomena, brain lesions, habits and other reasons. 1. Physiological phenomenon: the phenomenon of children suddenly shaking in their sleep, medically known as sleep myoclonus, is mainly due to the weakening of the brain’s control over the muscles. 2. Brain lesions: there may be a decline in the stability of the brain nerves, causing abnormal discharges in the central nervous system, which may appear to be always shaking. 3. Habits: 2-year-old children at this time of imitation is very strong, when someone around the phenomenon of shaking, may feel curious to follow the imitation, thus appearing in this situation. It is recommended that when a 2-year-old child is always shaking, go to the hospital in a timely manner, and follow the doctor’s instructions for treatment, to avoid delaying the condition.