The combination of elevated serum thyrotropin and normal serum thyroxine is called compensated or subclinical hypothyroidism. This most commonly represents clinically silent autoimmune thyroiditis. Whether this condition warrants treatment or simply observation is still debated. The risk of developing overt hypothyroidism is high in females with elevated thyrotropin above 10 mU/l and/or positive thyroid microsomal antibodies. Males are also at high risk of progression towards overt hypothyroidism, regardless of antibody status or degree of thyrotropin elevation. We advise routine treatment of only those at high risk of developing overt hypothyroidism.