Nephritis and nephropathy, not specified as acute or chronic, with lesion of membranous glomerulonephritis

This code identifies kidney inflammation and disease characterized by membranous glomerulonephritis, where the specific onset (acute or chronic) is not documented. It indicates a pathological change in the glomerular basement membrane, leading to proteinuria and potential renal dysfunction.

Use this code when documentation confirms a diagnosis of membranous glomerulonephritis without explicit mention of acute or chronic status. This is appropriate for biopsy-confirmed cases or when clinical findings strongly suggest this specific glomerular lesion but the chronicity is undetermined.

• Ensure documentation clearly specifies "membranous" glomerulonephritis; otherwise, a more general code for unspecified nephritis may be appropriate.
• If the documentation later clarifies the acute or chronic nature, update the code to a more specific option (e.g., 581.1 for acute, 582.1 for chronic).
• Always sequence this code as a primary diagnosis when it is the reason for the encounter, or as a secondary diagnosis if it's a co-morbidity impacting patient care.