The thyroid gland is located in the front of the neck, just below the voice box (larynx). It produces chemicals (hormones) that help the body control metabolism. Thyroid hormone is normally produced in response to another hormone released by the pituitary gland.
There are four main types of thyroid disease:
Hyperthyroidism -- too much thyroid hormone
Hypothyroidism -- too little thyroid hormone
Benign (noncancerous) thyroid disease
For information about a specific type of thyroid disease, see one of the following:
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.