Doctor's Note: Keeping It pHresh Down There

pH is a measure of the acid-base balance of a substance. Its range is 0 to 14 with zero being very acidic (hydrochloride acid) and 14 being very basic (bleach, drain cleaner); 7 is neutral—think water.

The pH of healthy vaginal fluid in reproductive-age women is between 4 and 4.5, due to high circulating levels of estrogen. Estrogen causes the vaginal tissue to produce glycogen, which helps promote the growth of lactobacilli. The lactobacilli create lactic acid, which is why vaginal secretions are on the lower end of the scale.

In addition to estrogen status, vaginal pH can also be affected by lubricants, semen, douches and certain medications. The only time knowing vaginal pH is helpful is to distinguish between certain types of vaginal infections, although there are usually better ways to determine this information.

Doctors and medical professionals can use pH paper to help determine the pH of vaginal secretions by touching the paper to the vaginal sidewall and comparing the color on the paper to a chart. In the presence of certain vaginal infections, the pH is usually elevated.

Some kits allow you to test your vaginal pH at home, but how useful this is to the average person is questionable and what you would do with this information is also a bit mysterious.

If you're concerned about your vaginal pH, you are probably having some symptoms, which we will talk about below. If you are having symptoms, save your money on the over-the-counter tests, because you're probably right in assuming your pH is off.

Your vagina is amazing

Yes, the vagina is a pretty incredible organ. Your vagina is elastic: It can stretch to accommodate a baby and still shrink back to allow for normal and enjoyable intercourse.

It also looks after itself. The vagina is like a self-cleaning oven. It maintains a healthy level of normal vaginal bacteria to prevent the overgrowth of harmful bacteria. These bacteria are present in vaginal secretions, which is partly why it is normal to have vaginal discharge throughout your cycle. Depending on where you are in your cycle, what medications you are taking and whether you are ovulating, your discharge may be thicker or slightly thinner at different points in the cycle.

I see at least one patient every week with concerns about normal vaginal discharge and spend a lot of time reassuring patients that discharge is not considered abnormal unless any of the following are present:

• Green/gray-colored discharge
• Fishy odor
• Itching or burning of the vagina or vulvar tissues

What about that odor?

First of all, who said vaginas had to smell like flowers? They are vaginas. They smell like vaginas.

Multiple product lines are marketed to women to make their vaginas "smell better," but they really aren't necessary and can sometimes cause problems by eliminating the "good" bacteria.

Douching is terrible for the normal bacteria in your vagina and should never be done. Ever. Please don't douche!

If you do notice an unpleasant body odor, it is likely related to sweat or odor coming from the perianal area because when those bacteria are exposed to air, they start to smell. This also happens to men because everyone who has an anus is capable of body odor. Blaming this phenomenon on the vagina is simply unfair unless, of course, there's an abnormal discharge or a fishy odor.

In a nutshell, if your vaginal discharge does not smell fishy or foul and is white or light yellow in color, and you do not have symptoms of itching or burning, your vaginal pH is likely just fine and there is no reason to be testing it or treating it.

If you notice a fishy smell, greenish or clumpy, thick white discharge, or symptoms of burning or itching, pick up the phone and make an appointment so a medical professional can diagnose and treat you appropriately.