The causes of high blood homocysteine are related to genetic factors, kidney failure and nutritional factors. High blood homocysteine levels are an undesirable phenomenon, and high blood homocysteine accelerates aging in the body. The causes of high blood homocysteine are: 1. malnutrition, if not taken folic acid and vitamins will affect the body’s vitamin and folic acid content, so that too much blood homocysteine accumulates in one place, which leads to elevated blood homocysteine. 2. kidney failure, which may cause elevated blood homocysteine, studies have shown that the blood homocysteine level in patients with kidney disease is 2-4 times higher than normal. 3. genetic factors, which may cause elevated blood homocysteine. 3. genetic factors, if blood homocysteine enzyme is missing due to gene deletion or gene mutation, it will affect the level of blood homocysteine, which will lead to high blood homocysteine level.