A high homocysteine level is generally indicative of a vitamin B12 or folate deficiency, and can also indicate a higher risk of cardiovascular disease. 1. Vitamin B12 or folic acid deficiency: The normal reference range for homocysteine in the human body is less than 15 μmol/L, and the diagnostic criterion for hyperhomocysteinemia is greater than or equal to 15 μmol/L. Homocysteine needs to be broken down and metabolized by the action of vitamin B12 and folic acid, so an elevated homocysteine level may imply that there is a vitamin B12 or folic acid deficiency. Therefore, elevated homocysteine may indicate vitamin B12 or folic acid deficiency. 2. High risk of cardiovascular disease: Studies have shown that elevated homocysteine is associated with a high risk of cardiovascular disease. It is believed that elevated homocysteine will easily damage the endothelium of blood vessels, triggering lipid deposition and atherosclerotic plaque formation, thus increasing the risk of cardiovascular and cerebrovascular diseases. If homocysteine is found to be elevated, it is recommended to consult a doctor for further examination, and follow the doctor’s instructions for examination and treatment.