Goitre (sometimes spelled goiter) is a swelling of the thyroid gland that can be associated with either normal or abnormal thyroid hormone production. There are 2 main types; diffuse goitre where the whole gland is swollen and feels smooth to touch, and nodular goitre where the gland feels lumpy to touch.

There are many possible causes, including; hyperthyroidism (overactive thyroid), hypothyroidism (underactive thyroid), hormone changes during puberty/pregnancy/menopause, insufficient iodine in the diet, some medications, thyroiditis (inflammation of the thyroid), radiotherapy for cancer, harmless cysts, and thyroid cancer. Symptoms can include coughing, a tight feeling in the throat, changes to the voice, difficulty swallowing and breathing. Other symptoms will depend on the underlying cause. Treatment will depend on the underlying cause, ranging from observation to radioiodine treatment or surgery.