Blood pressure 80/100 mmHg pulse pressure difference is too small may be pericardial effusion, severe mitral stenosis, aortic stenosis and other causes; different causes of different treatment methods. 1. Pericardial effusion: pericardial effusion leads to compression of the heart, weakening of the pumping function of the heart, lowering of systolic blood pressure, leading to a decrease in the pulse pressure difference; it is feasible to perform pericardial puncture and drainage to relieve the pressure of pericardial effusion on the heart. 2. Severe mitral stenosis: severe mitral stenosis leads to the left atrium blood can not flow into the left ventricle, reducing the blood volume of the left ventricle, resulting in a significant decrease in systolic blood pressure, while the diastolic blood pressure does not drop significantly, thus reducing the pulse pressure; can be performed percutaneous balloon mitral valvuloplasty or prosthetic valve replacement. 3. Aortic valve stenosis: aortic valve stenosis leads to a decrease in the amount of blood pumped out of the heart, resulting in a significant decrease in systolic blood pressure and thus a decrease in the pulse pressure difference; prosthetic valve replacement or percutaneous aortic valve balloon angioplasty can be performed. Blood pressure 80 ~ 100 mmHg pulse pressure difference is too small patients should go to the hospital in a timely manner to improve the examination, clear cause of the disease to give targeted treatment.