What diseases can be detected by the five thyroid function tests?

　　The term "five thyroid function tests" refers to the standard panel of five tests used to evaluate thyroid function. Generally, these tests can detect conditions such as hyperthyroidism, hypothyroidism, Hashimoto's thyroiditis, subacute thyroiditis, and thyroid tumors. Detailed explanations are as follows:

　　1. Hyperthyroidism

　　This condition is primarily characterized by decreased thyroid-stimulating hormone (TSH) levels and increased levels of free triiodothyronine (FT3) and free thyroxine (FT4). Patients may experience symptoms such as excessive sweating, weight loss, and palpitations.

　　2. Hypothyroidism

　　In contrast to hyperthyroidism, patients with hypothyroidism typically show elevated TSH levels while FT3 and FT4 levels are decreased. Symptoms may include fatigue, cold intolerance, and edema.

　　3. Hashimoto's Thyroiditis

　　In the early stages of Hashimoto's thyroiditis, TSH, FT3, and FT4 levels may remain normal, but antibodies such as thyroid peroxidase antibodies (TPOAb) and thyroglobulin antibodies (TgAb) may be elevated. As the disease progresses, hypothyroidism may develop.

　　4. Subacute Thyroiditis

　　The five thyroid function tests may show decreased TSH with elevated FT3 and FT4 levels initially. As the condition progresses, these levels may return to normal or progress to show signs of hypothyroidism.

　　5. Thyroid Tumors

　　Although the five thyroid function tests cannot directly diagnose thyroid tumors, abnormal hormone levels may suggest the possibility of a tumor.

　　When undergoing the five thyroid function tests, results should be interpreted by a qualified physician, taking into account clinical symptoms and other diagnostic findings for comprehensive evaluation.