ABSTRACT
DEFINITION Hypothyroidism is a clinical syndrome associated with a failure of the thyroid glands to produce and release thyroid hormones1,2. It is classified as primary, secondary, or tertiary if the abnormality affects the thyroid gland, pituitary gland, or hypothalamus, respectively. Thyroid hormone is necessary for the initiation of the anagen (growth) phase of the hair cycle and normal metabolism of the skin.
