Not necessarily. It could also be “BV.” Here’s how to find out — plus why it’s important to get the right diagnosis.

In every issue of WebMD the Magazine, we ask our experts to answer readers’ questions about a wide range of topics. For our July-August 2010 issue, we turned to Terri Warren, RN, ANP, WebMD’s herpes and sexually transmitted diseases expert, to answer a question about diagnosing vaginal infections.

Q: I have a thick vaginal discharge, and I feel burning throughout the day. could I have a yeast infection?

A: maybe. It’s possible you have one of several conditions. With a yeast infection, most often caused by an overgrowth of the fungus Candida albicans, you might notice a clumpy white discharge, itching, burning, and redness of the labia.

Another possibility is bacterial vaginosis (BV), caused by an imbalance of good and bad bacteria in the vagina. although BV often has no symptoms, you might notice a thin, grayish discharge, itching, and burning — and a distinctive fishy odor, especially after sexual intercourse.

Getting the right diagnosis is important. Left untreated, BV is not only unpleasant but could increase your risk of pelvic inflammatory disease, pregnancy complications, and sexually transmitted diseases such as HIV, chlamydia, gonorrhea, and herpes. and while yeast infections can be treated with over-the-counter topical or prescription oral medications, BV is treated with either vaginal or oral antibiotics, available only by prescription.

Which do you have? Don’t diagnose yourself. See your doctor right away. more might be going on than you think.