The normal range of serum homocysteine is 5-15 μmol/L. When it is greater than 15 μmol/L, it can be called hyperhomocysteinemia, 15-30 μmol/L is mildly elevated, 30-100 μmol/L is moderately elevated, and greater than 100 μmol/L is severely elevated. Current research has found that hyperhomocysteinemia is a risk factor for hypertension, coronary heart disease, stroke, chronic kidney disease, and other diseases, and that its causes are related to enzyme deficiencies, cofactor deficiencies, excessive methionine intake, certain diseases, and the effects of some medications. Hyperhomocysteinemia is mainly treated with folic acid and vitamin B12 supplementation. Apart from that, a healthy lifestyle, such as eating a balanced diet, stopping smoking and drinking, and increasing the amount of exercise appropriately, can help lower homocysteine. When hyperhomocysteinemia is detected, it is necessary to go to the hospital for consultation and follow the doctor’s instructions for treatment.