The head is always dizzy, can be caused by physiological or pathological factors, pathological causes include cerebral atherosclerosis, cervical spondylosis, neurasthenia and so on. 1. Physiological factors: if a long time without exercise, inactivity, always maintain a posture, in the occasional activity, it is easy to brain blood supply is insufficient, and then produce the phenomenon of dizziness and fainting, and more accompanied by shortness of breath and other manifestations. If you don’t eat for a long time, it is easy to lead to the occurrence of hypoglycemia, insufficient cerebral blood supply and even anemia, which will lead to dizziness. 2. Cerebral atherosclerosis: usually occurring in middle-aged and old people, cerebral atherosclerosis will lead to slowing down of the blood flow, as well as the elasticity of the blood vessels, narrowing of the lumen, so the blood will be in the state of viscosity, leading to insufficient blood supply to the brain, which will lead to dizziness and fainting symptoms. 3. Cervical spondylosis: cervical spine bone lesions can squeeze the cervical vertebral artery, resulting in insufficient blood supply to the brain, which in turn makes the head always dizzy. 4. Neurasthenia: usually due to anxiety, nervousness, lack of sleep, which can lead to excessive brain fatigue, which in turn leads to a decline in brain function, resulting in dizziness. 5. Other: carbon monoxide poisoning, pulmonary encephalopathy, hepatic encephalopathy, etc., can cause systemic oxygen supply, which leads to the symptoms of dizziness. In short, when the phenomenon of dizziness occurs, it is recommended to go to the hospital in time for a clear examination and targeted treatment.