[Diagnosis in urinary tract infections].

For a rational diagnostic work-up of urinary tract infections (UTI), a detailed history and a standardised examination of smear material, prostatic fluid and urine are essential. Examination of the urine is simple, with test strips, microscopic examination of the sediment and determination of the bacterial count by the dipstick procedure having proved their worth in practice. Isolation and identification of pathogens and the preparation of an antibiogram require special knowledge of microbiological techniques. Accurate evaluation of the urine and its constituents requires a knowledge of how the urine has been collected; we recommend spontaneously passed urine in men and young children, and catheter urine in women. Acute complicated and chronic recurrent UTIs require radiological studies and sonography. Occasionally, nuclear-medical investigations and angiography or CT may be necessary for detailed classification. In cases of obstruction of the lower UT or neurogenic problems with urinary bladder, urodynamic investigation and endoscopy must be performed. This stepwise diagnostic evaluation allows both optimal classification of the UTI and a saving in costs.