Regular hemodialysis at Newcastle upon Tyne has been shown to be associated with the progressive development of bone pain and radiological abnormalities, the most prominent being alteration of the trabecular pattern (seen best in the hands), a reduction in cortical thickness, and pathological fractures (seen most commonly in the ribs) which remained unhealed for long periods. Subarticular sclerosis developed in most patients. The usual features of hyperparathyroidism were inconspicuous, and those patients who demonstrated them usually did not have fractures. These changes are attributable to a combination of osteomalacia, osteoporosis, and hyperparathyroidism. There is some evidence that the local water supply has something to do with it.