Acquired hemosiderosis resulting from massive iron deposits in various organs, including heart, liver, and pancreas, may lead to architectural and functional disturbances of these organs. Even though iron overload can occur in nonuremic as well as in uremic individuals, the dialysis patient is at particular risk for developing hemosiderosis. Many dialysis patients receive exogenous iron from either oral iron therapy or blood transfusions. In addition, these patients seem to be at high risk for retaining iron. A diagnosis of excess iron deposition should be considered if the patient has unexplained cardiomyopathy, hepatic cirrhosis, proximal myopathy, diabetes mellitus, arthropathy, or immune dysfunction such as listeriosis. Several techniques are available for determining iron overload. Diagnostic tests include measuring serum ferritin levels, staining bone marrow preparations for excess iron, measuring tissue hemosiderin concentrations, magnetic resonance imaging, and the deferoxamine (DFO; Desferal) "challenge test." The simplest treatment for iron overload in nonuremic patients is removal of iron by venesection. However, in patients in whom venesection is not feasible, the chelating agent DFO can effectively remove excess iron. In the dialysis patient, DFO therapy can be combined with either dialysis or hemoperfusion to remove the iron-DFO complex that would otherwise be removed by the kidney. DFO therapy in the nondialyzed individual has proven to be successful, but before treatment, the benefits of the treatment must be weighed against possible adverse side effects such as cataracts, changes in color vision, and anaphylaxis. In the dialysis patient, indications for iron removal are less clearly defined.(ABSTRACT TRUNCATED AT 250 WORDS)