A foggy and swollen head may be due to physiological reasons, such as lack of sleep. It may also be caused by pathological reasons, such as high blood pressure, insufficient blood supply to the cerebral arteries, etc., and the cause should be identified in a timely manner. 1. Physiological causes: when the quality of sleep is poor, lack of sleep, mental stress or excessive use of the brain, this situation will lead to swelling of the head, adequate rest can effectively alleviate the symptoms. 2. Pathological causes (1) High blood pressure: High blood pressure is the most common cause of the above symptoms, after the blood pressure is under control, the symptoms of foggy head will be relieved. In addition, if the blood pressure fluctuates greatly, it will also cause dizziness and swelling of the head, and it is necessary to control the blood pressure in time. (2) Insufficient blood supply to the cerebral arteries: mostly seen in elderly patients with hypertension, diabetes, hyperlipidemia, etc., due to chronic blood supply disorders in the brain, there may be symptoms of swelling of the head, as well as memory loss, dizziness and other uncomfortable symptoms. If you exclude physiological reasons, you should consult a doctor in time to clarify the cause of the disease and then target treatment.