The excretory system keeps the body in homeostasis with the kidney, the main excretory organ maintain homeostasis through osmoregulation it maintains the water balance of our bodies . Whenever we need water and haven't drunk any the kidney nephrons limit urine output and whenever we've eaten too much sweet/salty stuff we get the feeling of thirst brought about by osmoreceptors in the kidney which sends a message to our hypothalamus which brings about the feeling of thirst and you'd then drink water to satisfy that thirst and flush your blood of the extra salts/sweets.
Symptoms of kidney failure are due to the build-up of waste products in the body that may cause weakness, shortness of breath, lethargy, and confusion. Inability to remove potassium from the bloodstream may lead to abnormal heart rhythms and sudden death. Dialysis is the artificial process of eliminating waste (diffusion) and unwanted water (ultrafiltration) from the blood. Our kidneys do this naturally. Some people, however, may have failed or damaged kidneys which cannot carry out the function properly - they may need dialysis.