For the doctors' arrival at home, the order amount must be more than 50 AZN. Homocysteine (HCYS) is a metabolic product of cysteine and methionine. It is an amino acid homocysteine. It needs folic acid, B6 and B12 for its metabolism. With their deficiency, an increase in the level of homocysteine is possible. An increase in homocysteine causes damage to the vessel wall (cholesterol accumulates in the vessel wall, atherosclerotic nodules form). If homocysteine is elevated in the blood, creatinine, vitamins TSH, B9, B12 should also be checked.