Goitre. Artwork comparing a healthy (left) and enlarged (goitre, right) thyroid gland (lower centre, blue). An enlarged thyroid may result from hormonal imbalances, an iodine (mineral) deficiency or autoimmune diseases. This swelling can result in difficulties in either breathing of swallowing. It is treated according to the under- lying cause, these include an improved diet and partial or total removal (thyroidectomy) of the thyroid gland. The thyroid is an endocrine gland that secretes the hormones thyroxine & calcitonin, which regulate energy levels and body metabolism.