thyroid gland disease
Diseases of the thyroid gland can result in either production of too much (overactive thyroid disease or hyperthyroidism), too little (underactive thyroid disease or hypothyroidism) thyroid hormone, thyroid nodules, and/or goiter. Thyroid problems are much more common in women than in men. Defects in these regulatory pathways rarely may result in hypothyroidism (underactive thyroid problem) or hyperthyroidism (overactive thyroid problem). 2  The most common cause of hypothyroidism and hyperthyroidism occurs due to problems within the thyroid and not the regulatory system.