If a patient has dizziness and nausea after a long time of head down, the following factors should be taken into consideration: 1. cerebrovascular insufficiency of blood supply, if a patient has cerebrovascular ischemia that leads to insufficiency of blood supply, dizziness accompanied by nausea and vomiting will occur when the head is down for too long. 2. if a patient has clear hyperlipidemia or high blood viscosity, dizziness accompanied by nausea will also occur when the head is down for a long time. 3. 3. If the patient has obvious cervical spondylosis, especially in the 2nd-7th cervical vertebrae disc protrusion or bulge, the patient will lead to compression of blood vessels and nerves after prolonged head down, which will also lead to dizziness and nausea. 4. If the patient with hypertension lowers his head for a long time, blood pressure regulation dysfunction and blood pressure fluctuation will occur, which will also lead to dizziness and nausea.