Free fatty acids as a predictive indicator, simple elevation does not have any obvious clinical symptoms, clinical symptoms need to be specifically combined with the primary cause of the disease. Free fatty acids (FFA), also known as non-esterified fatty acids, are substances formed by the decomposition of neutral fats, and their content in serum is very small. The normal value of the enzyme method (at 37℃) is 400-900 μmol/L, and there are no obvious specific clinical symptoms if they are simply elevated. However, elevated free fatty acids are commonly seen in the course of diabetes mellitus, hyperlipidemia, hyperthyroidism, and severe liver disorders, such as diabetes mellitus, in which the common symptoms are three more and one less, i.e., polydipsia, polyphagia, polyuria, and weight loss. In addition, long-term high-fat diet or lack of exercise may lead to high free fatty acids. If high free fatty acids are found, it is recommended to further improve the examination under the guidance of a physician to clarify the specific cause of the disease and then carry out targeted treatment.