It can cause extreme itching and burning in the vulva and surrounding area and can be very hard to cure. Yeast vaginitis is not a bacterial infection and is not caused by being dirty. In fact the opposite may be true.
Yeast is normally present in a healthy vagina and thrives in that warm, moist environment.
Some bacteria is also present and completely normal. These two work in balance with each other to promote a healthy pH balance in the vagina. Yeast vaginitis or yeast infection occurs when the naturally-occurring bacteria of the vagina are killed, allowing the yeast to overgrow. Frequent yeast infections can also indicate other underlying conditions such as diabetes, or suppressed immune system. Because the symptoms may mimic bacterial infections in the vagina and other conditions, including urinary tract infections, it's best to visit a doctor if you develop symptoms of yeast vaginitis.