Diagnosis of Vaginal Infections

The diagnosis of vaginitis starts with your doctor taking a careful history of your symptoms. After this, a pelvic exam will look for any signs of erythema (redness) and irritation in the vagina, as well as evaluate any discharge present. Your doctor will examine your cervix (opening to the uterus) to make sure that it shows no sign of associated infection.

During the physical exam, your doctor will likely take a sample of fluid or discharge from within the vagina. A number of tests can be performed on this fluid to determine the cause of the vaginitis:

  • pH – the pH is the measure of acidity in the vaginal fluid. A pH of more than 4.5 is suggestive of bacterial vaginosis or trichomonas. A pH of less than 4.5 is suggestive of candida.
  • Amine test (whiff test) – a drop of potassium hydroxide is added to the vaginal fluid sample. A resulting ‘fishy’ odor is suggestive of bacterial vaginosis.
  • Wet mount – wet mount refers to looking at the sample under a microscope with a drop of either saline (salt water) or potassium hydroxide added. With trichomonas, the parasite can often be visualized, along with a large number of inflammatory cells. The branching pattern of the candida fungus can be seen in candida vaginitis. An increased number of round bacteria versus rod-shaped bacteria and special cells called ‘clue cells’ are suggestive of bacterial vaginosis.
  • Vaginal cultures – if the results of the other tests do not provide a clear answer, your doctor may send the sample for a culture, which involves waiting for a period of time to see what organism grows in the sample.