1) Acute Glomerulonephritis :-
Is know to follow acute infection & characteristically presents as acute nephritic syndrome. Acute post streptococcal glomerulonephritis is most common form of glomerulonephritis in children 6-16 yrs of age.

Grossly– The kidneys are symmetrically enlarged weighing one or 1½ – twice the normal weight. The cut section show petechial haemorrhage (small spot under the skin due to effusion of blood) giving the characteristics appearance of “flea-bitten kidney”(unpleasant appearance).

Microscopically-Glomeruli are affected diffusely. They are enlarged & hypercellular, due to proliferation of tuft (bunch or collection) mesangial, epithelial or endothelial cells. Tubules may show swelling, there may be interstitial oedema & leucocytic infiltration.

2) Rapidly Progressive Glomerulonephritis  :-
It present with acute renal failure in few weeks or month.
Grossly– The kidney are usually enlarged & pale with smooth outer surface. Cut surface shows pale cortex & congested medulla.
Microscopically-Crescents(curved sickle shape) are seen inside the Bowman’s capsule.
Glomerular tufts frequency contain fibrin thrombi.

3) Chronic Glomerulonephritis :-
End stage kidney is the final stage of a glomerular disease.
Grossly– The kidneys are usually small & contracted, weighing as low as 50 gm each. The capsule is adherent to the cortex & the cortical surface is generally diffusely granular.

Microscopically– Glomeruli are reduced in no. & show completely tuft appearing as eosinophillic masses.
– Many tubules completely disappears, may be atrophy of the tubules close to scarred glomeruli.
– There is fine delicate fibrosis of the interstitial tissue & varying no. of chronic inflammatory cells