The causes of not high blood pressure but dizziness and nausea are as follows:1. Cerebrovascular diseases should be considered, such as transient ischemic attack, acute cerebrovascular blood supply insufficiency, cerebral infarction, cerebral embolism, all of which can cause dizziness and nausea but not high blood pressure.2. For peripheral metabolic diseases, such as thyroid dysfunction and adrenocortical dysfunction, the above conditions are usually also found.3. Chronic Cardiac insufficiency, in total heart failure, the patient will not have high blood pressure, but dizziness, nausea, accompanied by chest tightness, shortness of breath, palpitations, dyspnea, sedentary respiration, jugular vein filling and so on. 4, for the endocrine metabolism class of other diseases, such as the body’s imbalance in the secretion of estrogen and progesterone, especially in the women’s menstruation period or before and after the menopause, prone to the above situation.