Head trembling when head down is seen in the following diseases: 1, to consider the nerve root type cervical spondylosis, because in the nerve root type cervical spondylosis occurs when head down, that is, when the cervical spine is flexed, the cervical intervertebral foramen gap or narrowing can easily cause nerve root compression pressure, which may cause head trembling at this time. 2, but also to consider the head and neck muscle injuries and muscle spasms, in the muscle spasms will occur in the head and neck rigidity When the head is lowered, the neck muscles will be pulled, which will make the neck muscle spasm aggravate, and cause muscle contracture and twitching, which will cause the head to shake.