The vagina creates its own environment and maintains a balance among the normal bacteria found there and the hormonal changes in a woman's body. Vaginitis occurs when the vaginal ecosystem has been changed by certain medications such as antibiotics, hormones, contraceptive preparations (oral and topical), douches, vaginal medication, sexual intercourse, sexually transmitted diseases, stress, and change in sexual partners.

A woman who has had one vaginal yeast infection can usually recognize its symptoms if it recurs. And a woman who has had several infections has no doubt about what's wrong when the next yeast infection starts. Another symptom is a thick, mostly odorless discharge. But this can be misleading because discharge in and of itself is not diagnostic. If you have a white discharge with an intense irritating itch, you may have an infection. Unfortunately, many women will, in response to increased estrogen at mid-cycle and the increased production of cervical mucus, develop a white, curdy discharge. That is not a yeast infection.

Candida infections in the mouth are often called "thrush." Symptoms include creamy white patches that cover painful areas in the mouth, throat, or on the tongue. Because other infections cause similar symptoms, it's important to go to a doctor for an accurate diagnosis.

Wearing artificial fingernails increases the chance of getting yeast infections under the natural fingernails. Fungal infections start in the space between the artificial and natural nails, which become discolored. Treatment for these types of infections -- as well as those that occur in other skin folds, such as underarms or between toes -- require different products, most of which are available only with a doctor's prescription.

Another cause of yeast infection is a generally weakened or deficient immune system. How does the immune system get worn down enough to be a cause of yeast infection in the average person? Many times a person has had an illness or injury and their health is never the same again. The body has been damaged too severely for the immune system to repair the cells properly, although it never stops trying. Over time, the immune system weakens to the point it can no longer defend the body. Instead, it focuses on other processes more important for continued life.

The essential oil tea tree oil, applied topically to the vaginal area, has shown some potential as a natural remedy for yeast infections. A compound called terpinen-4-ol in tea tree oil appears to be responsible. Unfortunately, there haven't been any clinical studies in humans showing that tea tree oil is effective or safe for yeast infections. Until we have more evidence, it should not be recommended. Full strength tea tree oil should never be applied to the vaginal area.

Various topical creams may be used to relieve itching or irritation of the vulva (folds of skin on the outside of the vagina). Oral medications may be necessary, but these can be obtained only by prescription from a physician.