Evaluation of voluntary urination and measurement of the post-voiding residue enabled the identification of 6 groups among 1,025 patients 83 +/- 7 years old: 400 normal patients (N); 97 with retention but without incontinence (R); 133 incontinent without retention (I); 50 incontinent with retention (IR); 236 who failed to urinate voluntarily (MO); 109 with indwelling catheters (SAD). Incontinence and indwelling catheters were more common in women; men more frequently failed to urinate voluntarily (p < 0.01). The IR and SAD groups had more urinary infections (p < 0.01) and included more invalids (p < 0.001). The MO and SAD groups had more demented members (p < 0.001) and a higher death rate (p < 0.001). Management consisted of a 48-hour diary of urinations (R and IR groups), scheduled micturitions (I and MO groups) and treatment of urinary infections. Evaluation of bladder sphincter function (n = 291) showed that bladder hypoesthesia was prevalent in groups R and IR and that bladder hyperactivity was predominant in groups I, MO and SAD. Among the 314 patients discharged from the hospital, 181 were reevaluated: good results were obtained for 43% of the initially incontinent and for 53% of those with retention. The indwelling catheters were removed from 82% of the SAD group.