Some diseases of the thyroid or pituitary gland cause the thyroid to make too much or not enough thyroid hormone: Doctors use blood tests to check for thyroid or pituitary problems. In kids already ...

Explain what to expect during the test. If your child is anxious about it, work together on ways to stay calm. Thyroid peroxidase (TPO) is an enzyme made by the thyroid gland. The thyroid uses iodine, ...