This month's clinical practice guideline (CPG) review is on the diagnosis and treatment of hyperthyroidism and hypothyroidism as provided by the American Association of Clinical Endocrinologists. An estimated 27 million Americans have thyroid disease, and about 13 million of them are undiagnosed. The risk of thyroid disease increases with age, and women are seven times more likely than men to develop thyroid problems. Unfortunately, thyroid symptoms are usually very nonspecific and should be kept in the differential diagnosis of many clinical complaints. The format of this month's column is a little different because we received two independent manuscripts, each of which had merit. We made a decision to present both points of view and deleted repetitive material. This is an example of variable approaches one can take with reviewing and critiquing CPGs.