Not all cases of subclinical hypothyroidism require medication, but subclinical hypothyroidism is a pre-malignant manifestation of hypothyroidism, which is mostly found during physical examination. Subclinical hypothyroidism is characterized by elevated TSH and normal T3 and T4. Some subclinical hypothyroidism can develop into clinical hypothyroidism, some subclinical hypothyroidism may return to normal, and some subclinical hypothyroidism will continue to maintain the state of subclinical hypothyroidism. Therefore, not all subclinical hypothyroidism needs treatment. The following subclinical hypothyroidism needs treatment: 1. Subclinical hypothyroidism with TSH greater than 10.0mU/L may lead to hypercholesterolemia and aggravate the development of atherosclerosis, which needs to be treated with levothyroxine sodium tablets for replacement. If the TSH is less than 10.0mU/L, no treatment can be given. 2. If subclinical hypothyroidism is found during pregnancy or in women with childbearing requirements, regardless of whether the TSH exceeds 10.0mU/L, levothyroxine sodium tablets should be given for replacement therapy to avoid affecting fetal development.