[Kidney function and kidney diseases in the elderly].

The significance of age-induced alterations in renal function is described in order to explain clinically important entities in older people, such as hypo- and hypervolaemia, hyper- and hyponatraemia, hyperkalaemia and metabolic acidosis. A sound knowledge of the age-dependent changes in renal function enables the physician to effectively prevent many of these metabolic disturbances. Renovascular disease, nephrotic syndrome, renal cysts and acute renal failure are renal diseases which typically have a higher incidence in older people and require special consideration when evaluating renal disease in the elderly.