Normally, Candida has a yeast-like form which can attach to any surface whether biological or inanimate. When it heads into the human body, it finds a nice place on our skin cells. Here, it can grow happily without causing any damage. But, if there are any stresses, such as an immune response, a change in pH or an alteration of salt and iron concentrations, the friend turns into a foe as it begins to produce a number of molecules known as invasins, which break down the same cells it considered to be a home. At this point, the fungus switches from the yeast form into a true fungus producing long extensions known as hyphae, which give it a characteristic furry look. Once this happens, it's a declaration of war.