Management of subclinical hyperthyroidism (low TSH and normal thyroid hormones) is controversial. Knowledge of its causes, clinical context and associated morbidity is required. It is recommended to follow six steps in exploration and treatment: 1) confirmation, 2) estimation of severity, 3) cause assessment, 4) study of complications, 5) balance whether treatment is needed and 6) if necessary, choice of the most appropriate form. In its management, the same treatments are used as in overt hyperthyroidism.