High cysteine refers to higher than normal levels of homocysteine in the blood. It is mainly related to genetic factors, nutrient deficiencies, abnormal kidney function, cardiovascular disease, drug factors, and other factors such as hypothyroidism. 1. Genetic factors: gene mutation or congenital genetic defects, so that homocysteine in the process of metabolism lack of metabolic enzymes, thus causing homocysteine accumulation in the body. 2. Nutrient deficiencies: when the human body lacks vitamin B6, vitamin B12 and folic acid, the metabolism of homocysteine will be abnormal, thus causing the accumulation of homocysteine in the body. 3. Abnormal renal function: in patients with renal failure, the metabolism and clearance rate of homocysteine in the body decreases, thus causing an increase in the value of homocysteine. 4. Cardiovascular diseases: patients with coronary heart disease and cerebral infarction can also be found with increased homocysteine values. 5. Drugs: Some anti-tuberculosis drugs and anti-tumor drugs will affect the metabolism of homocysteine in the body, thus making the value of homocysteine higher. 6. Other factors: patients with hypothyroidism, as well as with aging, smoking, drinking, etc. can increase the value of homocysteine in the body. If you find that homocysteine is elevated, you should go to a regular hospital in time to have the cause clarified and receive treatment under the guidance of your doctor.