What is the definition or description of: interstitial nephritis?

Kidney disease: Inflammation of interstitium of kidney can cause kidney not to function well and accumulation of toxins. There can be some abnormalities in urine also. Some medications , infections or connective tissue disorders can cause it.

Inflammation : Usually caused by an inflammation of the interstitium (the small spaces between cells), often triggered by an identifiable drug or agent causing "hypersensitivity" reactions of the cells. Often resolves with stopping the offending agent. Supportive care is usually adequate for resolution, if it is acute.