Considering a human body, homeostasis happens when our body regulates the body temperature to maintain an inner temperature of almost 98.6 degrees Fahrenheit. Literary speaking, it is like sweating to get rid of heat during the summer season or shivering during winters to produce heat to beat the decreasing temperature. Claude Bernard and Walter Bradford Cannon are responsible for systematic research on this biological process. Homeostasis happens in both endothermic animals (birds and mammals) and exothermic animals (reptiles and certain species of sea animals). Endothermic species maintain a steady body temperature and their exothermic counterparts do it via body temperature variation.
It is said that the humongous growth of our species was due to our homeostatic regulations, as it provides a mechanism to adjust to a wider range of environments. Animals which use small amount of energy to maintain homeostasis eat less, like some reptiles that are known to live without food for a longer time interval. Biologically speaking, most of the homeostatic regulations are controlled by release of hormones into bloodstream. Kidneys eliminate the extra ions and water from the blood via urine. Hence, kidneys perform the process of homeostatic regulation by removing waste or excess products from a body of a mammal.
Homeostatic imbalance is the inability to maintain homeostatic regulations. This may lead to diseases or even death in some cases. Giving an example, heart failure does occur when harmful 'positive feedback mechanisms' take over and 'negative feedback mechanisms' become plagued. Homeostatic imbalance is responsible for many diseases like diabetes, hypoglycemia, gout, hyperglycemia and even dehydration. Homeostatic imbalance causes many other diseases which occur due to the presence of some kinds of toxins in the bloodstream.