The applicability of 1H NMR urinalysis to glomerulonephritis was investigated: storage of urine at -18 degrees C and its subsequent lyophilization were shown to cause no loss of available biochemical information. Proteinuria was demonstrated not to interfere with the breadth and intensities of 1H NMR signals of low-molecular-weight metabolites in urine. The urine content of patients with glomerulonephritis was shown to be independent of exogenous factors, whereas these factors did affect the content of the urine of healthy volunteers. Statistical analysis of 1H NMR data for 52 patients with glomerulonephritis and 8 healthy volunteers on a pseudo-nephrological diet allowed the confirmation of the obligatory tubular interstitial changes that accompany the disease progression. It was established that severe tubular interstitial distortions can be revealed in patients with clinically preserved kidney function who display early stages of the glomerulonephritis, whereas these distortions can be practically negligible even at the terminal phase of uremia. Among patients with clinically preserved kidney function, especially those with nephrotic variant of the disease, isolated tubular and papilla distortions, as well as simultaneous tubular interstitial changes, were discovered, and this complicated the prognosis of glomerulonephritis progression. Thus, a new criterion to unmask a group at risk of rapid progression to uremia can be proposed, justifying an early prescription of immune suppressive drugs or other adequate treatment to these patients.