What Is a Yeast Infection?

Most people with vaginas have heard of a yeast infection — it’s an extremely common condition that can wreak havoc on both your vagina and your everyday life. 

You may be less familiar with the how and why of a yeast infection, which comes down to Candida, the type of fungi that causes it. 

Candida (yeast) lives on our skin and in various nooks and crannies within, including the mouth, throat, and vagina. Though fair amounts of Candida can be found in the vaginal microbiomes of healthy people, sometimes, Candida can overgrow and become a yeast infection. 

If you’ve had one or think you might have one, you’re far from alone — up to 75% of women will have a vaginal yeast infection at least once in their lifetime. 

Vaginal yeast infections can be anything from mild and annoying to severe and recurring. Given their prevalence, it’s important to understand the signs, symptoms, and causes of yeast infections, so that you know how to best care for your body and when to seek treatment.

What does a yeast infection look like?

Perhaps the most obvious visual sign of a vaginal yeast infection is a change in discharge. You’ve maybe heard of the “cottage cheese” analogy (how did vaginal infections get stuck with the worst descriptors?) and true to it’s comparison, a yeast infection creates discharge that is a whitish-yellow color with a curdish consistency. Another sign of infection can be swelling and soreness of the vulva. 

What does a yeast infection smell like?

One indication that it may NOT be a yeast infection? A fishy smell. 

If yeast infections create odor, many will note that it smells — well — yeasty (like beer or bread), though some people feel there is no smell at all. However, if you are experiencing a smell you would characterize as foul, rotten, or fishy, it may be a different condition such as BV, trichomoniasis, or gonorrhea—in which case it’s best to seek medical attention ASAP. 

In addition, an Evvy test can uncover all bacteria and fungi in your microbiome and help you track how changes in your microbial composition are related to symptoms like odor. 

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Yeast infection symptoms: what does a yeast infection feel like? 

Most people associate a yeast infection with itchiness — a symptom caused by inflammation of the vulva and vagina. However, it can cause other symptoms, too. 

The symptoms of a vaginal yeast infection may include:

• Vaginal and vulvar itching, redness, or soreness
• White vaginal discharge, that is curd-like in consistency and does not often smell 
• Pain during sex 
• Soreness or stinging when you pee — this happens when the urethra is inflamed, too 
  

A yeast infection is the second most common cause of soreness and swelling in and around the vagina (after BV), with the most typical symptoms being itching, burning, and redness. However, these can also be a sign of other conditions, so be sure to get checked out by a doctor if you’re actively having symptoms! 

How is a yeast infection diagnosed? 

If you suspect you have yeast infection, your doctor will first ask you about your symptoms and medical history and then do a pelvic exam, where they will examine your vulva and vagina for signs of infection including swelling, redness, and abnormal discharge. Like many other gynecological exams, doctors may use a speculum to examine the inside of your vagina and cervix. 

Your doctor may also take a swab of the inside of your vagina, which can be examined under a microscope or in the lab for signs of yeast species. While treating by phone — or even online questionnaire — is becoming increasingly more common, advocating for a yeast culture vs. relying on symptoms alone can help to prevent misdiagnoses and unnecessary antifungal overuse. 

Think twice before self-diagnosing

As some types of medication used to treat yeast infections are available over-the-counter, many people also choose to self-diagnose. But self-diagnosing isn’t always reliable, as other infections can often be mistaken for a yeast infection!  

In one study of 601 cisgender women, only around half self-diagnosed their yeast infection correctly. Another analysis of 153 patients found that 74% were incorrect in diagnosing themselves with a yeast infection, while in yet another, only 61% of BV and 77% of yeast infection diagnoses among 220 people were incorrect. You get the idea!

What’s more, using antifungals or other yeast infection products when you don’t have one may irritate your vulva/vagina or exacerbate conditions like bacterial vaginosis (BV) or cytolytic vaginosis (CV).  

Fact check: Can men get yeast infections?

People with penises can also get yeast infections from sex! It’s estimated that around 15% of people with a penis who have unprotected penetrative sex with someone with a yeast infection go on to develop a penile yeast infection. 

Yeast infection treatment 

Generally, antifungal medicines are considered first-line treatment for yeast infections. Your doctor will recommend treatment depending on how severe your infection is and how frequently it recurs, if at all.

If you have mild or moderate symptoms that do not recur frequently (also sometimes called an “uncomplicated infection”), you may be prescribed a short course of vaginal antifungal medicine in cream, ointment, or suppository form. Those are the ones that often end in “-azole” like terconazole or miconazole.  Alternatively, you may be given a single, oral dose of a medicine called fluconazole — which isn’t recommended if you are pregnant. 

For more severe or frequent infections, you may need to take multiple oral doses of antifungal medication or be prescribed a longer course of vaginally-inserted antifungal medications. 

If the infection isn’t responding to antifungal drugs, then your doctor may recommend other medicines such as boric acid, nystatin, or flucytosine, which can be taken as a vaginal suppository. 

What if my yeast infection doesn’t respond to treatment?

Sometimes, a yeast infection doesn’t clear up, even when you’re taking medication. If this is you, don’t panic—it could be because that particular medication doesn’t work on the type of yeast that’s causing your infection. 

The majority of yeast infections—up to 90%, in fact—are caused by a type of Candida called Candida albicans (C. albicans), but there are other strains that can overgrow in the same way. These include Candida glabrata (C. glabrata), which is responsible for around 5% of cases, plus C. tropicalis, C. parapsilosis, and C. krusei, among others. 

Treating different strains of Candida

When an infection is caused by a yeast other than C. albicans, it’s clinically labeled as a “complicated infection”. This means that your doctor may suggest different types of treatment, including a longer or higher-strength dose of medication, or that you should take different medicines together. 

For example, first-line antifungal treatment for C. albicans infections is not as effective on other strains, while certain antifungal treatments may not always be effective on an infection caused by C. glabrata, and your doctor might recommend boric acid instead. The vaginal cream terconazole is recommended for infections caused by yeasts other than C. albicans and C glabrata. 

Taking treatment for the wrong yeast might also explain why your infection keeps coming back. It’s always best to check in with your doctor if your yeast infection isn’t responding to treatment. It may be the case that your symptoms are being caused by something else, such as cytolytic vaginosis (CV)—when “good” bacteria overgrow—which can also be itchy and cause vaginal discharge.

(Curious what bacteria and types of Candida are present in your vaginal microbiome? Explore our Vaginal Health Test. 

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What causes a yeast infection?

There's no sure-fire way to prevent a yeast infection from happening, and how effective any precautions are can depend on individual factors—including your medical history and sexual behaviors. However, here are some common factors that can cause Candida to overgrow.

Antibiotics

Antibiotics are the most frequent and predictable cause of a yeast infection. Various studies have shown that yeast infections are more common in those who are taking antibiotics, but exact numbers differ depending on the size and location of the study. 

Despite there being a clear association between antibiotics and Candida overgrowth, the reason why is still TBD by further scientific research (yet another question we hope Evvy can help answer!) It’s important to note that all classes of antibiotics—not only antibiotics for vaginal issues—can increase risk. 

People who have some Candida present—at a healthy level—prior to taking antibiotics are at a higher risk of a post-antibiotic yeast infection as well. An Evvy Test can inform you regarding the presence and amount of Candida in your vaginal microbiome.

Estrogen levels

The sex hormone estrogen can play a role in the development of a yeast infection. This is why they are more common during pregnancy, when estrogen levels are raised, and in people who take hormonal contraception. 

Compromised immunity

People with a weakened immune system, for example those with HIV, are more susceptible to Candida overgrowth.

Diabetes

Yeast feeds off sugar, so uncontrolled blood sugars can encourage yeast to overgrow. 

Chemicals and fragrances

When used to clean the vagina, irritants such as perfumed soaps, shower gels, and feminine hygiene products can alter the vagina’s natural pH, creating favorable conditions for Candida overgrowth 

Remember, you also don't need to clean out your vagina with any sort of liquid or gel—it's self-cleaning! 

Tight clothing

Synthetic and poorly-ventilated clothing are also thought to increase the risk of infection, as this can increase the temperature and moisture levels around the perineal area—between the anus and the vulva—and cause Candida to overgrow. However, more research is needed here. In the meantime, the CDC suggests wearing cotton underwear.  

Sex

Yeast infections are not a sexually-transmitted infection, but sometimes sexual activity can create conditions that encourage Candida to overgrow. 

Get care for yeast infections with Evvy

‍We've created the first-ever platform for vaginal healthcare that combines state-of-the-art vaginal microbiome testing, prescription treatment, and 1:1 coaching to get you the answers, relief, and support that you deserve.

Built with leading OB-GYNs and researchers, Evvy's care platform can connect you to providers trained to review your vaginal microbiome results and select the best antifungal to decrease your specific strains of Candida (including ones that aren't often tested for at the doctor's office.)

They'll also recommend research-backed supplements to build back your microbiome to a protective state.  Experience vaginal health care with Evvy today.