Homocysteine 17μmol/L, which exceeds the upper limit of normal, is an abnormality, suggesting that the patient has an increased risk of cardiovascular disease, diabetes, and other diseases, and requires prompt intervention. Homocysteine is one of the products of metabolism and synthesis of substances essential for life activities. A plasma homocysteine level of 10 μmol/L or more is called hyperhomocysteinemia. Hyperhomocysteinemia is associated with the development of many diseases and can be used as an indicator of disease risk. For patients with cardiovascular diseases such as coronary artery atherosclerosis, the risk of cardiovascular disease increases with every 5 μmol/L increase in the level of homocysteine; in terms of tumorigenesis, the incidence of digestive tract tumors is increased by 7% with every 5 μmol/L increase in the level of homocysteine. In terms of tumorigenesis, for every 5 μmol/L increase in plasma homocysteine, the risk of type 2 diabetes mellitus increases by 1.29 times. The prevention and treatment of hyperhomocysteinemia lies mainly in prevention, which can be achieved through measures such as a healthy diet and medication such as methylcobalamin to reduce the risk of the disease. For homocysteine abnormalities, it is recommended to visit a hospital or undergo a systematic health check to avoid delaying the disease.