Routine gynecological examinations can often identify vaginitis that is not accompanied by noticeable symptoms. Therefore, it is important for women to annually visit their gynecologist (a physician who specializes in treating disorders of the female reproductive system). Women who experience signs and symptoms of vaginitis should immediately notify their gynecologist unless they have been previously diagnosed with a yeast infection and the signs and symptoms are identical.

Diagnosis of vaginitis typically begins with a medical history, followed by a pelvic examination. Women should avoid douching or using deodorant sprays before their medical examination because these products can impede the diagnosis of vaginitis.

If bacterial vaginosis (BV) is suspected, the gynecologist will measure the acidity or pH level of the patient’s vagina using narrow-range pH paper. The normal vaginal pH of premenopausal women is approximately 4.0 on the 0 to 14 pH scale, with 7.0 being neutral. A pH of 4.5 or greater may indicate that the patient has BV. The gynecologist will also typically take a sample of the patient’s cervical or vaginal discharge for analysis under a microscope. The sample will be examined for “clue cells,” bacteria-covered cells in the patient’s vaginal lining that indicate the presence of BV. In addition, the gynecologist may add potassium hydrochloride to a vaginal discharge specimen and check its odor (whiff test).

Women who have had yeast infections in the past often believe that they can diagnose an infection without consulting their gynecologist. However, misdiagnosis of yeast infection is common. Therefore, women should schedule a gynecological appointment unless they are certain that they have a yeast infection, and not another condition that presents similar symptoms.

To diagnose a yeast infection, the gynecologist will examine the vagina for abnormal discharge or inflammation. The physician will also collect secretions from the vaginal area and view the specimens under a microscope to determine if the infection is present due to a yeast organism (slide test). This test is generally sufficient for diagnosing yeast infections in first-time sufferers and those with occasional infections. However, cases of recurrent or resistant yeast infections may require further analysis in the form of a vaginal culture, which is used to identify the presence of other forms of vaginitis as well as sexually transmitted diseases.

Trichomoniasis may also be detected by measuring the acidity or pH level of the patient’s vagina using pH paper. However, the condition is typically diagnosed by examining a vaginal fluid sample under a microscope for the presence of parasites (protozoa). This technique, called a “wet mount,” is accurate only about 50 percent of the time because the protozoa can be difficult to find, and are often mistaken for normal cells. Researchers are developing more reliable tests for diagnosing this condition.

Diagnosis of viral vaginitis typically depends on the type of virus present. For instance, the human papillomavirus (HPV) can sometimes be detected along with a Pap smear (a screening procedure that detects changes in the cervix) or through special DNA probe tests that can determine the type of HPV virus.