If you've had a yeast infection, you've probably also had a lot of questions about the connection between sex and yeast infections. Here are some answers.

Women dread the intense itching and thick, white discharge that signals the presence of a vaginal yeast infection. (In case you're curious, Candida albicans is the scientific name of the yeast that usually causes these infections.)

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.

According to the Centers for Disease Control and Prevention (CDC), 75 percent of women will have at least one vaginal yeast infection in their lifetime. But the diagnosis of a yeast infection is a bit more complicated than simply having yeast in the vagina.

Yeast can be present in or around the vagina and not cause symptoms, a situation known as colonization. Diseases like HIV and diabetes, certain medications and being pregnant increase the chances that an overgrowth of yeast will occur and cause the unpleasant symptoms typically associated with a vaginal yeast infection.

While it's not considered a sexually-transmitted disease, like chlamydia or gonorrhea, some sex practices increase the likelihood of developing a vaginal yeast infection. So in order to help clear up some commonly asked questions about yeast infections, here are some answers.

Is Yeast in My Vagina Normal?

Yes! A healthy vagina normally hosts a large number of bacteria and sometimes yeast. As described in a September 2000 article published in American Family Physician, Lactobacillus acidophilus is the primary bacteria in a healthy vagina and up to 50 percent of women without symptoms also have yeast in their vagina.

Lactobacillus secretes hydrogen peroxide, which helps keep the vagina as a slightly acidic environment. This keeps other organisms in check, preventing their overgrowth.

But a fragile balance exists in this little ecosystem. Diabetes, oral sex, pregnancy and antibiotics can alter the vaginal environment, sometimes sufficiently to allow other organisms such as yeast to overgrow and cause symptomatic infections.

Read more: 13 Things That Should Never Go Near Your Cooch

Why Do I Get Yeast Infections After Sex?

Sexual activity in and of itself doesn't cause vaginal yeast infections. However, sexual intercourse can introduce yeast into the vagina, which might later overgrow and cause a symptomatic infection.

An October 1997 study published in Genitourinary Medicine reported that 16 percent of men studied had yeast colonization of their penis. The rate was similar between heterosexual and homosexual men and the majority of these men had no symptoms.

So it's possible for sex between a man and a woman to introduce yeast from the man's penis into the woman's vagina. But again, yeast introduced into the vagina doesn't necessarily mean a symptomatic infection will develop.

Can You Get a Yeast Infection From Too Much Intercourse?

Women and the medical community have long wondered whether the frequency of sexual activity influences the risk for vaginal yeast infections. And the answer is similar to the one above — not really.

A study published in November 2000 in the Journal of Women's Health and Gender-Based Medicine examined whether there was an association between the frequency of sex and the frequency of vaginal yeast infections. The researchers found no increase in symptomatic yeast infections based on the frequency of sexual activity.

A few earlier studies suggested that more sex might lead to more vaginal yeast infections, but the more recent study mentioned above, which included 248 women, was clear in its declaration that there is no association. Notably, the CDC does not list frequent sexual activity as a risk factor for vaginal yeast infections.

Read more: The 10 Most Annoying Women's Health Issues and How to Fix Them

Can Saliva Cause a Yeast Infection?

So on the other hand, it appears that receiving oral sex might lead to more yeast infections. A study published in February 2004 in Sexually Transmitted Infections found that receiving oral sex increased the likelihood of having a vaginal yeast infection.

The article in the Journal of Women's Health and Gender-Based Medicine noted the same finding. The association may be due to direct transmission of yeast from the mouth of the person giving the oral sex to the vagina of the person receiving oral sex — as roughly 30 percent of healthy people have Candida albicans in their mouth.

Another possible explanation might be the development of a mild abrasion of the vaginal mucosa during oral sex, giving yeast present in the vagina an opportunity to overgrow. As previously noted, the vaginal environment is delicately balanced and the introduction of any foreign substance — including those in saliva — may be enough to throw off that balance.

Can You Have Sex With a Yeast Infection?

Technically, you can have sex with a yeast infection (as long as you've confirmed with your doctor that it is, in fact, a yeast infection and not an STD). However, most doctors recommend that you wait until the infection clears to resume having intercourse.

Besides the fact that having sex with a yeast infection might be uncomfortable, you may also make your yeast infection symptoms worse with all that friction and even prolong healing time. And you should definitely avoid oral sex while you have a yeast infection.

See your doctor as soon as possible and before you have sex again to avoid potential spread of a sexually transmitted disease. Your provider can perform testing, make a diagnosis and provide any necessary treatment.

How Long Does a Yeast Infection Last?

Fortunately, the majority of vaginal yeast infections that are diagnosed because of itching, pain and discharge are easily and quickly treated, with resolution of symptoms in two to three days (or sometimes less).

Topical over-the-counter (like Monistat) and prescription anti-fungal products (like Diflucan) that are applied to the vagina and vulva for one to three days work well for most women.

The remaining 10 to 20 percent of infections are more difficult to treat. This can be due to an infection that persists despite using a topical anti-fungal medication, which most often occurs because a type of yeast other than Candida albicans is causing the infection.

Recurrent or chronic yeast infections, defined as four or more symptomatic yeast infections within one year, can also be more difficult to treat. Some vaginal yeast infections present with severe symptoms, and some woman have a disease such as HIV that makes treatment more challenging and requires a longer course of medication.

Read more: 9 Things You Should've Learned in Sex Ed

Warnings and Precautions

Even though yeast infections are not a sexually transmitted disease, they share symptoms with STDs, which are common and have potentially significant health impacts. Any change in vaginal discharge, pain with sex or unexpected vaginal bleeding should prompt a visit to your healthcare provider to rule out STDs as the cause.

Pregnancy is a time when yeast infections are particularly common and the types of medications used are important. Any vaginal symptoms during pregnancy, including itching, pain, bleeding or change in discharge, should be evaluated immediately by your healthcare provider.

Reviewed by: Tina M. St. John, M.D.