Thyroid hormones include tetraiodothyronine (T4) and triiodothyronine (T3), and their reduction mainly reflects the abnormalities of thyroid function, which has certain effects on the function of the liver. 1. Thyroid hormone can regulate the initiation of mitochondrial osmotic activity in the liver. When T3 and T4 are reduced, the biosynthesis of hepatic glutathione is reduced, and the stability of glutathione cannot be maintained, which results in the change of liver function. 2. Thyroid hormone can enhance lipoproteinase activity. When T3 and T4 are reduced, the reduction of thyroid hormone decreases lipoproteinase activity, cholesterol synthesis is greater than catabolism, and elevated lipids increase lipid droplets in the hepatocytes, resulting in localized inflammation, necrosis, swelling and rupture of cell membranes, and enzyme release. Whether liver function is affected is also related to the degree and cause of the decrease in T3 and T4, etc. If a decrease in T3 and T4 is detected, it is recommended to improve other tests under the guidance of a doctor.