A friend says she has it and must avoid sugar and foods made with yeast.
Yeasts live almost everywhere, including on the skin and in the mouth, vagina, and intestinal tract.
They're usually harmless, but at times can cause problems. In most people such infections are minor, but they can be serious, especially in people with suppressed immune systems, such as those with cancer, AIDS, or severe diabetes. The general yeast syndrome you mention is different, however. Popularized in the early 1980s by two books, which were mostly collections of anecdotes and odd theories, this syndrome goes by many names, such as yeast hypersensitivity or chronic candidiasis. According to proponents of this theory, yeast overgrowth is very widespread and leads to suppression of the immune system and scores of health problems and diseases.