Kidney Disease (Renal Disease): Causes, Symptoms, & Treatments Link 2: DOWNLOAD [PDF] Link 2: Download [PDF] Our kidneys are some of the most essential organs in the human body. They serve a multitude of purposes, perhaps most importantly and notably as the main player in the urinary function of the body. Kidneys not only filter the blood in a body, but they also remove wastes and toxins for excretion, and maintain blood pressure by regulating a proper salt and water balance in the body. Kidneys also regulate various metabolic activities through their hormonal secretions, and maintain the acid-base balance in the body. Without our kidneys, our body would be unable to function at all, which is why kidney disease can be a tragic and dangerous condition. There are a number of different diseases that afflict the kidneys. Perhaps the most common is kidney stones, but chronic kidney disease is arguably the worst, in terms of the impact that i...