A large thyroid nodule refers to an abnormal growth or enlargement of the thyroid gland, which is a butterfly-shaped gland located at the base of the neck. Generally, a nodule is considered large if it measures more than 1 centimeter in diameter. While most thyroid nodules are benign and do not cause any symptoms, a large nodule may be more concerning and require further evaluation. Some common symptoms associated with a large thyroid nodule include neck swelling, difficulty swallowing or breathing, hoarseness, or a visible lump in the neck. In some cases, a large thyroid nodule may be a sign of thyroid cancer, although the majority of cases are benign nodules.