The advanced stage of a group of kidney disorders, resulting in inflammation and gradual, progressive destruction of the glomeruli (internal kidney structures). Damage to the glomeruli with subsequent inefficient filtering causes blood and protein to be lost in the urine. Because symptoms develop gradually, the disorder may be discovered when there is an abnormal urinalysis during routine physical or examination for unrelated disorders. It may be discovered as a cause of hypertension that is difficult to control.
The disorder is rare, affecting only 4 out of 100,000 people.