Sporadic enlargement of the thyroid gland that is not associated with changes in thyroid function or malignancy. The disease is Monarch Disease Ontology id MONDO_0001658 (nontoxic goiter). Also known as: Nodule-thyroid, non tox, euthyroid goiter, euthyroid goitre, goiter, non-toxic, non-toxic goiter, non-toxic goitre, non-toxic simple goiter, non-toxic simple goitre.