Why is the back of the left head numb and dizzy?

Left side of the head numbness, halo, sink, can drink cervical spondylosis has a certain relationship, cervical disc protrusion, cervical spondylosis stimulate blood vessels and nerves, can cause cerebral vasospasm, can cause vertebrobasilar artery blood supply deficiency, can show left side of the head numbness halo sink situation, need further head CT, head magnetic resonance blood vessels, anti-platelet aggregation, blood circulation, circulation improvement, lipid regulation, plaque stabilization treatment, can also cooperate with acupuncture, physiotherapy, massage, hot compress and other treatments. It may also be related to intracranial lesions and space-occupying lesions, and other diseases need to be further excluded.