Glomerulonephritis: Inflammation of the Glomeruli

Biology · Excretory Products and Their Elimination · NEET

Glomerulonephritis means inflammation (swelling) of the glomeruli of the kidney. The glomerulus is the tiny ball of blood capillaries where blood is filtered, so when it is inflamed, filtration is disturbed and proteins or blood cells may leak into the urine. Memory hook: "Glomerulo + nephr + itis" = glomeruli + kidney + inflammation.
Glomerulonephritis: Inflamed Glomerulus vs Healthy GlomerulusHealthy GlomerulusClean filter: only waterand small wastes passInflamed GlomerulusLeaky filter: protein andblood cells escape into urine
Glomerulonephritis is inflammation of the glomeruli. The swollen, damaged filter becomes leaky, so proteins and blood cells (purple dots) that should stay in the blood escape into the urine.

Your doubts, answered

What exactly is inflamed in glomerulonephritis?

Only the glomeruli are inflamed. The glomerulus is the ball of blood capillaries sitting inside the Bowman's capsule, and it is the site where blood is filtered. NCERT states it in one line: 'Glomerulonephritis: Inflammation of glomeruli of kidney.' It is NOT inflammation of the whole nephron or the whole kidney.

How is glomerulonephritis different from renal calculi (kidney stones)?

They are two separate kidney disorders and NEET loves to swap them. Renal calculi are a hard mass of crystallised salts (like oxalates) formed inside the kidney. Glomerulonephritis is inflammation of the glomeruli. One is a solid stone, the other is swelling of the filtering capillaries.

Why does glomerulonephritis affect urine formation?

Ultrafiltration happens at the glomerulus. When the glomeruli are inflamed, the fine filtering membrane is damaged, so large molecules like proteins and even blood cells can leak into the filtrate. This means the urine may contain protein or blood, which normally should stay in the blood.

Is glomerulonephritis the same as uremia?

No. Uremia is a high level of urea in the blood, which happens when the kidney fails to remove urea. Glomerulonephritis is the inflammation of glomeruli itself. Severe or long-term glomerulonephritis can damage the kidney and lead towards kidney failure, but the two terms mean different things.

Which part of the nephron is linked to this disorder?

The glomerulus, which is part of the Malpighian body (renal corpuscle) along with Bowman's capsule. Filtration (ultrafiltration) occurs here. So glomerulonephritis directly hits the filtration step of urine formation, not reabsorption or secretion in the tubules.

⚠️ The NEET trap
Glomerulonephritis is inflammation of the whole nephron or the entire kidney tissue.
Glomerulonephritis is inflammation of the glomeruli only, as NCERT states word for word.
🧠 Read the word: glomerulo = glomeruli, NOT nephron or kidney as a whole. In matching questions, pair 'glomerulonephritis' strictly with 'inflammation of glomeruli of kidney'.

Real NEET questions

2018

Match the items given in Column I with those in Column II and select the correct option given below: Column I a. Glycosuria b. Gout c. Renal calculi d. Glomerular nephritis Column II i. Accumulation of uric acid in joints ii. Mass of crystallised salts within the kidney iii. Inflammation in glomeruli iv. Presence of glucose in urine

A · a-ii, b-iii, c-i, d-iv
B · a-i, b-ii, c-iii, d-iv
C · a-iii, b-ii, c-iv, d-i
D · a-iv, b-i, c-ii, d-iii
Solution: Glycosuria (a) = presence of glucose in urine (iv); Gout (b) = accumulation of uric acid in joints (i); Renal calculi (c) = mass of crystallised salts within the kidney (ii); Glomerular nephritis (d) = inflammation in glomeruli (iii). So the correct match is a-iv, b-i, c-ii, d-iii.
2025

Match List-I with List-II List-I A. Emphysema B. Angina Pectoris C. Glomerulo-nephritis D. Tetany List-II I. Rapid spasms in muscle due to low Ca++ in body fluid II. Damaged alveolar walls and decreased respiratory surface III. Acute chest pain when not enough oxygen is reaching to heart muscle IV. Inflammation of glomeruli of kidney Choose the correct answer from the options given below:

A · A-II, B-IV, C-III, D-I
B · A-II, B-III, C-IV, D-I
C · A-III, B-I, C-IV, D-II
D · A-III, B-I, C-II, D-IV
Solution: Glomerulonephritis (C) is the only excretory-system disorder here and NCERT defines it as inflammation of the glomeruli of the kidney, so C matches IV. Emphysema = damaged alveolar walls (II), Angina Pectoris = chest pain from low oxygen to heart muscle (III), Tetany = muscle spasms from low Ca++ (I). Answer: A-II, B-III, C-IV, D-I.

Solved Excretory Products and Their Elimination NEET PYQs

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Frequently asked

What is glomerulonephritis in simple words?

It is the swelling or inflammation of the glomeruli, the tiny bunches of blood capillaries inside the kidney that filter the blood. NCERT defines it as 'Inflammation of glomeruli of kidney.'

Where in the kidney does glomerulonephritis occur?

In the glomerulus, which lies inside the Bowman's capsule in the cortex region of the kidney. Together they form the Malpighian body where blood filtration takes place.

Does glomerulonephritis cause protein in urine?

Yes, because the inflamed glomerular filter becomes leaky and allows proteins and sometimes blood cells to pass into the urine, which normally should not happen.

Is glomerulonephritis the same as nephritis?

Nephritis is a general term for kidney inflammation. Glomerulonephritis is specific: it is inflammation of the glomeruli. For NEET, always use the exact NCERT line about the glomeruli.

Can glomerulonephritis lead to kidney failure?

If it is severe or long-lasting, the damage to the filtering units can reduce kidney function and may progress towards renal failure, which then needs dialysis or a kidney transplant.