[Hematuria and nephritic sediment].

Vigorous physical exercise is just as likely to be the cause of hematuria as are diseases of the efferent urinary tract, inflammatory renal disease or tumors. The microscopic search for dysmorphic erythrocytes (acanthocytes), casts or leukocytes in the sediment is a helpful technique for deciding the how to proceed with further diagnostic measures. Morphological changes in more than 17% of the erythrocytes are highly suggestive of a glomerular cause, Also, the presence of various casts points to kidney disease. The typical microscopic picture of interstitial nephritis is sterile leukocytosis. This may be of atheroembolic origin, medication-induced, or viral. In any case, the nephritic sediment should be clinically evaluated only in the context of further information such as the patient's age, comorbidities, or medication.