The possible causes of hypotension, i.e. low diastolic blood pressure, include hereditary hypotension, atherosclerosis, aortic valve insufficiency, pericardial effusion, and shock state. 1. Hereditary hypotension: these patients usually have low diastolic blood pressure and low systolic blood pressure. If there are no uncomfortable symptoms, there is no need for treatment, and attention should be paid to monitoring blood pressure. 2. Atherosclerosis: mostly seen in the elderly, diastolic blood pressure is the pressure of blood on the blood vessel wall during the diastolic period of the heart, the elderly have peripheral vascular sclerosis, the elasticity of the arteries and veins are reduced, the amount of venous blood returning to the heart during the diastolic period is reduced, and the diastolic blood pressure decreases. 3. Aortic valve insufficiency: due to the presence of aortic regurgitation, it is easy to cause high systolic pressure and significantly lower diastolic pressure, at this time, the patient’s pulse pressure difference increases, accompanied by aortic valve auscultation area murmur. 4. Pericardial effusion: Inflammation of the heart or trauma resulting in a large amount of pericardial effusion, affecting the diastolic function of the heart, resulting in a decrease in the preload of the heart, when the systolic blood pressure and diastolic blood pressure fall at the same time, with a certain degree of life-threatening. 5. Shock: In case of shock caused by various reasons and insufficient blood volume in body circulation, both systolic and diastolic blood pressure will drop, affecting the blood supply of important organs in body circulation and seriously affecting the functions of heart, brain, kidney and other organs. It is recommended that patients monitor their blood pressure regularly, and seek prompt medical attention and standardized treatment if there is any abnormality or discomfort.