Not to be confused with hemostasis. Homeostasis or homoeostasis (homeo- + -stasis) is the property of a system in which variables are regulated so that internal conditions remain stable and relatively constant. Examples of homeostasis include the regulation of temperature and the balance between acidity and alkalinity (pH). It is a process that maintains the stability of the human body's internal environment in response to changes in external conditions.
Allergies, also known as allergic diseases, are a number of conditions caused by hypersensitivity of the immune system to something in the environment that usually causes little problem in most people.
Allergies occur when your immune system reacts to a foreign substance â such as pollen, bee venom or pet dander â that doesn't cause a reaction in most people. Your immune system produces substances known as antibodies.