Glomerulonephritis Light micrograph of tissue from a kidney in a case of glomerulonephritis This condition refers to inflammation of the glomeruli (red structures), the filtering structures of a kidney In the chronic form, the renal glomeruli and tubes atrophy, turn fibrous, and fail Focal segmental glomerulosclerosis (FSGS) is one of the most common causes of primary glomerular diseases in adults Magnification: x 250 when printed at 10 centimetres wide