The organism must confront and control the balance of both pro-oxidants and antioxidants
continuously. The balance between these is tightly regulated and extremely important for
maintaining vital cellular and biochemical functions. This balance often referred to as the
redox potential, is specific for each organelle and biological site, and any interference of the
balance in any direction might be deleterious for the cell and organism. Changing the
balance towards an increase in the pro-oxidant over the capacity of the antioxidant is
defined as oxidative stress and might lead to oxidative damage. Changing the balance
towards an increase in the reducing power, or the antioxidant, might also cause damage and
can be defined as reductive stress.