What is subclinical hypothyroidism in a thyroid function test?

Subclinical hypothyroidism occurs when TSH levels are elevated, but T4 and T3 levels are still within the normal range. Individuals with subclinical hypothyroidism may not show any obvious symptoms of hypothyroidism, though some may experience mild fatigue or weight gain. This condition is often a precursor to full-blown hypothyroidism, especially if left untreated. Depending on your symptoms and TSH levels, your doctor may recommend monitoring or starting low-dose thyroid hormone replacement therapy to manage the condition and prevent progression.