Previously not seasick now seasickness, may be the following situations: First, because of psycho-psychological factors, when a person is in a state of emotional tension, anxiety, depression, etc., will lead to the regulatory function of the brain and the dysfunction of the central nervous system, will cause nerve overexcitation or excessive tension, causing abnormal discharge of brain cells, in the process of riding in the car will produce a certain stimulation of the brain, in the external stimulation will cause seasickness This can cause motion sickness under external stimulation. Second, it may be due to cerebrovascular diseases, such as cerebral infarction, cerebral embolism, cerebral thrombosis, etc. When these diseases cause changes in the blood flow state of the blood vessels, which can cause a reduction in blood flow, causing damage to the corresponding brain cells, brain nerve dysfunction, so that the normal neurological function can not be controlled in time, there will be dizziness.