Low diastolic blood pressure includes physiological causes, aortic valve insufficiency, hypothyroidism, etc., which can lead to insufficient perfusion of the heart, brain and kidneys, and cause dizziness, chest tightness and renal insufficiency. 1. Physiological causes: Some women and thin people may have low diastolic blood pressure, which is physiological and does not require special treatment and does not cause serious harm. 2. Aortic valve insufficiency: this can lead to regurgitation of blood, which reduces the blood volume of the aorta and can lead to lower diastolic blood pressure. 3. Hypothyroidism: A decrease in thyroid hormones can reduce the ejection volume of the heart and dilate the peripheral blood vessels, leading to lower diastolic blood pressure levels. Others, such as the elderly atherosclerosis is obvious can also lead to a reduction in diastolic blood pressure. Low diastolic blood pressure mainly causes insufficient perfusion of important organs, such as ischemia of the heart, brain and kidneys, which can lead to dizziness and chest tightness, and ischemia of the kidneys can lead to renal insufficiency. Patients with lowered diastolic blood pressure should go to the hospital in time, under the guidance of the physician to clarify the cause of the disease and timely treatment.