It maintain red cell level and calcium metabolism. A person with renal failure will know the important of kidney as waste accumulate causing harm to the body, blood pressure rises,red cell level falls causing aneamia bone is affected and fluid is retained causing swelling to mention a few consequences. What can damage its function? Drug like paracetamol,NSAIDs e.g ibuprofen,antibiotics e.g Gentamycin,antifugal e.g Amphoterin,radiocontrasr agents etc. Severe Dehydration. Blood loss. Diabetes mellitus. Hypertention. Cancer. Others are damage to organs such as heart failure,liver diseases etc. Common cause of long term problem is chronic glomerulonephritis,diabetes mellitus,hypertension,chronic and indiscriminate use of analgesics,herbal concotion,drinking green 'holy' water. The message is that dont play with your kiadney,dont jole with it,dont kid with it,You need them,they need you.