LDL cholesterol is below 3.4 mmol/L in normal people, so 3.18 mmol/L is a normal level. LDL cholesterol is a cholesterol-rich lipoprotein, a complex of cholesterol, protein and phospholipids. Its main role is to act as a carrier of cholesterol in the body to transport cholesterol to peripheral tissues for use by peripheral tissues. In normal adults, LDL cholesterol is below 3.4mmol/L, borderline at 3.4-4.1mmol/L, and elevated at over 4.1mmol/L. LDL cholesterol of 3.18mmol/L is normal, and this physiological indicator is closely related to atherosclerosis and other diseases. Familial hypercholesterolemia, diabetes, etc. may cause this value to rise, while cirrhosis of the liver and hyperthyroidism may cause this value to be too low. Eat more fresh vegetables and fruits, less high-fat food, pay attention to daily routine, and quit smoking and drinking if you have smoking and drinking habits. Make it a habit to have regular medical checkups so that if you have abnormal LDL cholesterol levels, you can have them adjusted and treated under the guidance of your doctor.