New methods for diagnosis of human dormancy syndrome are provided. Human dormancy syndrome is characterized by elevated serum ratio of rT3/fT3 compared to a population of normal subjects from which subjects suffering from fibromyalgia, chronic fatigue, obesity, dementias including Alzheimer's Disease and related dormancy conditions are excluded, and the presence of one or more findings related to reduced activity including torpor, chronic fatigue, insulin resistance, dementias, obesity and the like. Treatment of human dormancy syndrome is directed toward increasing fT3 levels or decreasing rT3 levels, or both, using pharmaceutical and/or behavioral methods. Other conditions that are associated with HDS can also be treated using T3 therapy, with or without specific psychological, behavioral or pharmaceutical therapies.