nephritis

DEFINITION of nephritis

The term nephritis refers to the inflammation of the kidneys. It is a broad category of conditions that can affect different structural parts of the kidney, including the filtering units (glomerulonephritis), the tubules and surrounding tissue (tubulointerstitial nephritis), or the renal pelvis (pyelonephritis). Etiologies range from bacterial or viral infections and toxic exposure to severe autoimmune processes (like lupus nephritis or IgA nephropathy). If untreated, acute nephritis can lead to progressive renal damage, culminating in chronic kidney disease (CKD) and end-stage renal disease (ESRD).

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ETYMOLOGY of nephritis

greek

Component	Origin	Meaning
nephr-	Greek nephros (νεφρός)	“Kidney”
-itis	Greek -itis (-ιτις)	“Inflammation” or “disease of”

The roots combine directly to form the literal medical definition: “inflammation of the kidney.” Historically, this condition was widely referred to as Bright’s disease in the 19th and early 20th centuries.

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🔀 ALIASES / ALTERNATE TERMS

• Kidney inflammation
• Bright’s disease (historical)
• Glomerulonephritis (GN) (when specifically affecting the glomeruli)
• Tubulointerstitial nephritis (TIN) (when affecting tubules/interstitium)
• Pyelonephritis (when involving the renal pelvis, typically infectious)

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🔗 RELATED TERMS

• Nephropathy — a general term for kidney disease or damage (e.g., diabetic nephropathy), which may or may not be inflammatory.
• Nephrotic syndrome — a kidney disorder causing massive proteinuria, often without the active cellular inflammation seen in nephritic syndrome.
• Pyelonephritis — specifically, a bacterial infection causing inflammation of the kidney and its pelvis.
• Hematuria — blood in the urine, a hallmark clinical sign of nephritic syndromes.
• Proteinuria — excess protein in the urine, indicating glomerular basement membrane damage.
• End-stage renal disease (ESRD) — complete or near-complete failure of the kidneys, sometimes the end result of chronic nephritis.

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CODING CORNER

🏥 ICD-10-CM CODES

Tubulointerstitial Nephritis

Code	Description
N10	Acute tubulointerstitial nephritis (also maps to acute pyelonephritis)
N11.9	Chronic tubulointerstitial nephritis, unspecified
N12	Tubulointerstitial nephritis, not specified as acute or chronic
N14.1	Nephropathy induced by other drugs, medicaments and biological substances

Glomerulonephritis / Nephritic Syndrome

Code	Description
N00.9	Acute nephritic syndrome with unspecified morphologic changes
N03.9	Chronic nephritic syndrome with unspecified morphologic changes
N04.9	Nephrotic syndrome with unspecified morphologic changes
N05.9	Unspecified nephritic syndrome with unspecified morphologic changes

Manifestation / Autoimmune (Requires Underlying Condition Code First)

Code	Description
M32.14	Glomerular disease in systemic lupus erythematosus (Code first SLE, e.g., M32.10)
M32.15	Tubulointerstitial nephropathy in systemic lupus erythematosus
M31.0	Hypersensitivity angiitis (Goodpasture’s syndrome)

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🔧 COMMON CPT CODES (Nephritis-Related Labs & Procedures)

CPT Code	Description
50200	Renal biopsy; percutaneous, by trocar or needle
76770	Ultrasound, retroperitoneal (e.g., renal, aorta, nodes), real time with image documentation; complete
81000	Urinalysis, by dip stick or tablet reagent… non-automated, with microscopy
82565	Creatinine; blood
82040	Albumin; serum, plasma or whole blood

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⚠️ Coding Note: Medical coders must carefully distinguish between nephritis (inflammation, often presenting with hematuria/RBC casts, i.e., “nephritic syndrome”) and nephrosis (podocyte damage leading to massive proteinuria and edema, i.e., “nephrotic syndrome”). Furthermore, always check for underlying etiologies. If the provider documents Lupus Nephritis, ICD-10 guidelines dictate “coding the underlying systemic disease first” (e.g., an M32.- code followed by M32.14 or M32.15). Look for acute kidney injury (AKI) codes (N17.9) if the inflammation has caused an acute drop in kidney function.

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DERIVATIONS of nephritis

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Query functionality

TABLE definition AS Definition
FROM #medterm 
WHERE length(filter(definition, (word) => econtains([[]].definition, word))) > 0 AND file.name != [[]].file.name

Med roots Appendix A Prefixes Appendix B Combining Forms Appendix C Suffixes Appendix D Suffix forms