Inflexibility of the left hand may be related to cerebrovascular disease, spinal cord cervical spondylosis, intracranial tumors, intracranial space-occupying diseases, which should be determined by the form of onset of the disease and the relevant examination.1 If the patient has a sudden onset of inflexibility of the left hand, which is caused by acute cerebrovascular disease, such as transient ischemic attack, cerebral infarction, cerebral hemorrhage, it will lead to adverse limb movement and inflexibility. The symptoms of unfavorable limb movement and inflexibility can be clarified by magnetic resonance brain imaging or CT examination of the head.2. If the patient has frequent episodes of inflexibility of the left hand, which is more likely to occur especially when the posture is not proper, the patient may consider that it is caused by spinal cervical spondylosis, and magnetic resonance examination of cervical spine can be done to clarify the inflexibility of limb movement due to compression of cervical spinal cord.3. If the patient has inflexibility of left hand, the symptoms of inflexibility persist, slowly and slowly, and the patient’s left hand is not flexible. If the symptoms of inflexibility persist, appear slowly, progress gradually and aggravate, it may be caused by intracranial tumors, intracranial occupations affecting the motor nerves, and it can be clarified by doing head CT and head MRI.