Subclinical hypothyroidism refers to a condition in which an individual has low levels of thyroid hormones, but does not exhibit any obvious symptoms. It is often diagnosed through blood tests that measure the levels of thyroid-stimulating hormone (TSH) and thyroxine (T4). In subclinical hypothyroidism, TSH levels are elevated because the body is trying to stimulate the thyroid gland to produce more hormones. However, the production of thyroid hormones by the gland may be reduced or impaired due to various reasons such as autoimmune disorders, iodine deficiency, or previous treatments like radioactive iodine therapy. While subclinical hypothyroidism does not cause any obvious symptoms, it can lead to other health problems if left untreated and may increase the risk of developing thyroid disorders in the future. Treatment for subclinical hypothyroidism typically involves hormone replacement therapy with synthetic thyroxine (levothyroxine) to normalize TSH and thyroid hormone levels.