Kidney inflammation. Light micrograph of a section through a glomerulus in glomerulonephritis. This is the acute (rapidly developing) form. Nephritis refers to kidney inflammation. Glomerulonephritis refers to inflammation of the filtering structure of a kidney, its glomerulus. It is usually caused by a bacterial infection, and may develop from a streptococcal throat infection. The glomerulus is a tightly coiled network of blood vessels. When the glomerulus is damaged, blood flow is reduced and so the filtration rate is slowed. Treatment is of any underlying infection, and bed rest to allow recovery. Magnification unknown.