Total cholesterol of 6.6mmol/L is not normal and is considered high. Total cholesterol level is affected by family, heredity, diet and other factors, the normal level of cholesterol should be less than 5.20mmol/L, total cholesterol 6.6mmol/L is elevated. Elevated total cholesterol should be ruled out firstly, if you eat high-fat food 1 day before the test, it can cause a transient increase in total cholesterol, in this case, after eating a light diet, the total cholesterol can usually be reduced to normal. Hyperlipidemia can increase the risk of cardiovascular and cerebrovascular diseases. If the total cholesterol is still high after eliminating the transient elevation caused by dietary factors, treatment should be carried out under the guidance of professional physicians.