In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

If a person has hypothyroidism , their thyroid gland does not make enough hormones .
Hypothyroidism , also called underactive thyroid or low thyroid , is a disorder of the endocrine system in which the thyroid gland does not produce enough thyroid hormone .