Vaginal yeast infections, also called Candida vaginal infections or candidiasis, are common and easily treated in most women. They are usually caused by an overgrowth of a fungus (genus: Candida) that lives in the body. Candida is always present in the vagina, mouth and gastrointestinal tract in small amounts, and normally it is kept in check by the body's own resistance and competition with other beneficial organisms. However, when an imbalance occurs, Candida can multiply and symptoms of candidiasis appear. It is unclear whether yeast infections are sexually transmitted, according to the National Institute of Allergy and Infectious Diseases (NIADD).
During a lifetime, 75 percent of all women are likely to have at least one vaginal Candida infection, and up to 45 percent have two or more, but these can be treated quite easily.
Vaginal yeast infections are the second most common cause of cases of abnormal vaginal discharge in the United States (the first is bacterial vaginosis). Women tend to be more susceptible to vaginal yeast infections
if their bodies are under stress due to poor diet, illness, lack of sleep and when they are taking antibiotics or corticosteroid medications.
Occasionally, a yeast infection may be an early sign of diabetes.Yeast infections may be more common around the time of a menstrual period. In a normal menstrual cycle, estrogen deposits glycogen (a form
of sugar) in the cells that are found in the lining of the vagina. The release of progesterone causes the cells to shed into the vagina, so the sugar becomes available for yeast to feed on, multiply and grow. Estrogen and sugar production peak at the midpoint between periods, and then progesterone begins to build and sugar is released.
Yeast infection symptoms can follow the hormonal pattern of this cycle. Usually, the most severe symptoms occur before the onset of a woman's period when more sugar is available. During and after the flow, symptoms are likely to subside. Additionally, changes in the vaginal pH can disrupt the immune system or destroy the so-called friendly bacteria that populate the vaginal canal and keep the yeast fungus in check.
