Atherosclerosis index is obtained by subtracting HDL from total plasma cholesterol and dividing by HDL. Atherosclerosis refers to the thickening, hardening, and loss of elasticity of the arterial wall due to a variety of pathologic factors, which may eventually lead to narrowing of the arterial lumen. The atherosclerosis index is generally used to assess the likelihood of atherosclerosis. The value is calculated by dividing the total cholesterol minus HDL by the HDL value, the normal reference value is less than 4, and the smaller the value, the lower the possibility of atherosclerosis and the lower the risk of cardiovascular and cerebral vascular diseases; the value is greater than or equal to 4, which means that atherosclerosis has already occurred, and the greater the value, the higher the risk of cardiovascular and cerebral vascular diseases. In conclusion, it is recommended to consult a doctor for standardized diagnosis and treatment when necessary.