[Urinalysis: what a primary care physician needs to know].

Dipstick urinalysis is a very useful diagnostic tool in primary care when used in a specific context (urinary complaints, follow-up of systemic diseases, or pregnancy), but not as a screening instrument. Urine collection in appropriate conditions, together with a correct interpretation of dipstick results, reduces the use of microscopic urinalysis and urine culture. Leucocyturia and positive nitrits indicate the presence of a urinary tract infection and do not generally require additional tests. Persistent haematuria or proteinuria need to be further explored (microscopic urinalysis and 24h urine collection). Presence of crystals in the microscopic urinalysis reflects the precipitation of the substance eliminated in the urinary tract, but does not systematically indicate a disease.