Low cholesterol is usually not important if it is caused by physiologic factors. If it is due to pathologic factors, it is important. Cholesterol is mainly an important component of cell membranes and can be used as an indicator for the assessment of lipid metabolism and atherosclerosis. The normal value is between 3.0 and 5.18mmol/L. If it is lower than 3.0mmol/L, it is in a low state. 1. Physiological factors, such as long-term dietary imbalance of partiality, but not eat meat food, so that the cholesterol intake is too low caused by, it is recommended to improve the lifestyle, balanced nutrition. 2. During menstruation, the rise in estrogen level will affect the cholesterol level and make the index appear low, which is caused by physiological factors and usually does not matter. It is recommended to moderate intake of animal offal and other cholesterol-containing foods, and to review the relevant indicators on a regular basis. 3. Pathological factors: If low cholesterol is caused by hyperthyroidism, cirrhosis, hepatitis and other secondary diseases, it is usually more important to actively treat the primary disease. Such as hyperthyroidism can choose methimazole, iodine 131 radiotherapy, etc., while cirrhosis, hepatitis can choose antiviral, hepatoprotective drugs. When the primary disease is cured, the index will gradually return to normal. When the above symptoms appear, it is recommended to go to the hospital in time for early and standardized treatment.