A blood pressure of 140/90 is mild hypertension and may cause dizziness. A blood pressure of 140/90 mmHg is considered mild hypertension. It is generally recognized that the standard value of normal blood pressure is less than 120/80mmHg. Most of the hypertension starts slowly and the clinical manifestation lacks specificity, and may present with headache, dizziness, palpitation, fatigue, tinnitus and blurred vision. Hypertension can be caused by genetic factors, environmental factors, obesity, medication or certain diseases, and can also be caused by emotional excitement, after exercise, emotional stress, etc. The symptoms of high blood pressure should be timely consultation, under the guidance of the doctor for treatment, daily attention to diet, eat less high oil, high fat and high sodium food, pay attention to balanced nutrition, no smoking and no alcohol, to develop the habit of daily monitoring of blood pressure, moderate physical exercise.