In 2004, john Hornberger of the American Academy of Dermatology organized a collaborative group of experts from more than 20 institutions to develop a diagnostic reference standard. The diagnosis is confirmed if the hyperhidrosis has been visible to the naked eye for at least 6 months without obvious cause and if two of the following conditions are met: (1) Bilateral symmetry of sweating areas. (2) At least one episode per week. (3) Age of onset is less than 25 years. (4) Positive family history. (5) No excessive sweating during sleep. (6) Interference with daily work life. If there is fever, night sweats, or weight loss, the possibility of secondary hyperhidrosis should be noted.