Understanding Yeast Overgrowth Flare-ups

Medically Reviewed by Traci C. Johnson, MD on May 28, 2024
4 min read

Yeast is a type of fungus that normally lives on your skin and in places like your mouth and intestines. It also lives in the vagina. Yeast is usually harmless, unless it grows too much. Then it can cause an infection called candidiasis.

You may discover that you have a yeast infection from symptoms like itching, redness, burning when you pee, and a white or yellow discharge from your vagina. Redness, itching, and soreness are signs of a yeast infection on your skin or in your mouth (which is called thrush).

About 3 out of every 4 women will get at least one vaginal yeast infection at some point in their lives. These infections are very common, and most are easy to treat with antifungal medicines.

It's important to treat yeast infections. In some women, they're more than just itchy and uncomfortable. If you let them go untreated, they can cause more serious health problems.

If you often get yeast infections, you'll want to find out what causes them so you can avoid those triggers.

Yeast infections happen when something upsets the balance of good bacteria (lactobacillus) and yeast in your vagina. As the yeast start to multiply too much, they grow into the deeper layers of the vagina. That overgrowth is what causes symptoms like itching, swelling, and discharge.

One thing to know about yeast is that they thrive in warm, humid conditions. Wearing tight or nonbreathable fabrics, keeping a sanitary pad in for too long, or sitting in a wet bathing suit or gym clothes for too long can increase your chance of getting a yeast infection.

Antibiotics also cause yeast infections. As these medicines kill the bacteria that cause infections like strep or pneumonia, they also kill off some of the healthy bacteria in your vagina. This leaves more room for yeast to grow.

It's important to only use antibiotics when you need them and follow your doctor's instructions. Taking an antifungal medicine at the same time as an antibiotic might also help prevent you from getting a yeast infection.

You're more likely to get yeast infections when your body is under a lot of stress. An illness, lack of sleep, and unhealthy diet can all stress your body out.

Having diabetes makes you more likely to get yeast infections. Diabetes is a disease of high blood sugar. Extra sugar in the blood spills over into your urine. Yeast feed on sugar.

High estrogen levels during pregnancy or when you take hormonal birth control also cause your body to make more sugar. That's why yeast infections are more common in pregnant women.

Though you can treat a yeast infection yourself, it's a good idea to see your doctor if this is your first one. Other types of infections, including bacterial vaginosis and the sexually transmitted infection (STI) trichomoniasis, have the same symptoms as yeast infections, but they're treated differently.

During the exam, your doctor will take a sample of discharge from your vagina. A lab will test the sample to confirm whether you have a yeast infection or something else.

Most of the time a yeast infection is more irritating than serious. Some infections clear up on their own without any treatment.

Still, it's important to get treated. Sometimes a yeast infection can get worse to the point where it causes swelling and cracks in the vagina.

Vaginal yeast infections are often easy to treat with a 1- to 7-day dose of antifungal medicine. These medicines stop yeast overgrowth in the vagina. You take them as a pill by mouth, or as an ointment or suppository that you put inside your vagina.

You can buy some topical antifungal medicines over the counter. For pills, you'll need a doctor's prescription.

Make sure you finish the whole dose of antifungal medicine. Stopping treatment too soon could let the yeast grow again.

A small number of women with yeast infections get systemic candida disease. This is a more serious infection that affects the blood, heart, brain, eyes, and other parts of the body. Systemic candida disease is more likely to affect women who have a weakened immune system – for example, because of HIV or cancer treatment.

Most women will get at least one yeast infection, but about 1 in 20 get four or more of these infections a year. Doctors call these recurrent yeast infections. Recurrent infections are more common in women who have diabetes or a weakened immune system.

If you get frequent yeast infections, your doctor may keep you on an antifungal medicine for a few months after your infection clears up to prevent future yeast infections. An antifungal has been approved to treat recurrent vaginal yeast infections for postmenopausal or permanently infertile women (including women who have had a hysterectomy, tubal ligation on both sides, or removal of the ovaries and fallopian tubes on both sides). 

Preventing yeast infections starts with figuring out what's causing your infections in the first place. You and your doctor can discuss things like the type of birth control or hormone therapy you take and whether you need to get tested for a condition like diabetes or HIV that increase the risk for yeast infections.