Hypothyroidism, or underactive thyroid, occurs when your thyroid gland is not making enough thyroid hormone. The thyroid gland is a butterfly-shaped gland that is located in your neck, just below the voice box or larynx. Thyroid hormone works to regulate your metabolism, or the way your body uses energy. Because the symptoms of hypothyroidism can disguise themselves as simple day-to-day ailments, many patients live with the condition for years before they seek treatment.1
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