The causes of dizziness and sinking on the back of the head are hypertension, cervical spondylosis, cerebellar or brainstem lesions, and chronic cerebral blood supply deficiency, as follows: First, hypertension: hypertension is a common cause of dizziness and lightheadedness, which can be relieved by taking oral antihypertensive drugs. Second, cervical spondylosis: cervical spondylosis is due to cervical spine osteophytes and herniated discs, which compress the corresponding blood vessels or nerves and can lead to the phenomenon of dizziness in the back of the head. Third, cerebellar or brainstem lesions: including cerebral hemorrhage, cerebral infarction after the sequelae, can also appear the phenomenon of dizziness in the back of the head. Fourth, chronic cerebral blood supply deficiency: for example, long-term hypertension, diabetes, hyperlipidemia, middle-aged and elderly friends, can appear the phenomenon of dizziness in the back of the head. Some of the above suggestions are for your reference only, but the specific needs to go to the hospital for consultation.