What Are the Most Common Vaginal Infections? Symptoms, Diagnosis, and Treatment

If you've noticed unusual discharge, itching, odor, or discomfort “down there,” you're far from alone. Vaginal infections are one of the most common reasons people visit their gynecologist, and the good news is that nearly all of them are quick to diagnose and treat once you know what you're dealing with. 

Below, we walk through the most common causes of vaginal symptoms, including two conditions that don't get talked about as often but are increasingly recognized: Candida glabrata and Mycoplasma genitalium. For each one, you'll find what to look for, how we diagnose it, and what treatment typically looks like. 

Worth knowing upfront: some of these infections can cause no symptoms at all, which is exactly why regular screening matters as much as watching for symptoms. 
 

The Most Common Vaginal Infections We See 

Yeast Infections (Vulvovaginal Candidiasis) 

A yeast infection happens when yeast overgrows in the vagina, most often a species called Candida albicans. A different species, Candida glabrata, is becoming more common and tends to behave quite differently, which is worth knowing before we get into symptoms. 

Symptoms 

Classic yeast infection symptoms include: 

• Intense itching and irritation of the vulva and vagina 
• Thick, white discharge often described as looking like cottage cheese 
• Redness and swelling 
• Pain or burning with urination or intercourse 

C. glabrata tends to show up differently. Symptoms are often milder and more subtle, sometimes just irritation or burning without the classic discharge, which makes it easy to miss or mistake for something else. 

Diagnosis 

Because the two species call for different treatment, getting the right diagnosis matters. At FPA Women's Health, we use nucleic acid (PCR) testing to identify the specific yeast species causing your infection, rather than relying on symptoms or a standard exam alone. This is especially useful for catching C. glabrata, which doesn't always show up clearly under older diagnostic methods. 

Treatment 

• Candida albicans: Standard treatment is an azole antifungal — either a short course of an over-the-counter or prescription vaginal cream/suppository (clotrimazole, miconazole, terconazole), or a single oral dose of fluconazole. For recurrent infections (three or more per year), a longer treatment course followed by maintenance therapy is often recommended. 
• Candida glabrata and other non-albicans species: These species are frequently resistant to standard fluconazole treatment, which is why identifying the specific species matters. Treatment usually involves a longer course (7–14 days) of a non-fluconazole azole. 

Bacterial Vaginosis (BV) 

BV isn't caused by one single organism. It develops when the vagina's normal balance shifts and the protective Lactobacillus bacteria that usually keep things in check get crowded out by an overgrowth of other bacteria. It's the most common cause of vaginal symptoms in women of reproductive age. 

Symptoms 

• Thin, grayish-white discharge 
• A distinct “fishy” odor, often more noticeable after sex 
• Mild itching or irritation 

Diagnosis 

At FPA Women's Health, we use nucleic acid (molecular) testing offering a more precise and sensitive diagnosis than older exam-based methods such as the traditionally used “Wet Mount.” 

Treatment 

First-line options include oral metronidazole taken twice daily for seven days, a metronidazole vaginal gel used once daily for five days, or a clindamycin vaginal cream used once daily for seven days. BV has a high recurrence rate, and up to half of women will have it come back within a year. 

If you're dealing with frequent recurrences, tell us. There's a newer conversation happening in gynecology worth knowing about: a 2025 clinical trial found that treating a male partner alongside the patient reduced how often BV came back, and the American College of Obstetricians and Gynecologists has since updated its guidance to say partner treatment can be considered for recurrent cases specifically. The CDC's treatment guidelines haven't caught up to this yet, so it isn't a routine recommendation across the board, but it's worth discussing with us if BV keeps returning. 

Trichomoniasis ("Trich") 

Trichomoniasis is a sexually transmitted infection caused by a small parasite called Trichomonas vaginalis. It's one of the most common curable STIs in the country, and many people carry it without noticing anything at all. 

Symptoms 

• Frothy, yellow-green discharge 
• Strong odor 
• Itching, redness, or discomfort with urination or sex 

Many people, both women and men, have no symptoms whatsoever. That's exactly why screening matters if you or a partner could be at risk. 

Diagnosis 

At FPA Women's Health, we diagnose trich with nucleic acid (NAAT) testing, which reliably identifies this specific parasite and is significantly more accurate than older diagnostic methods. 

Treatment 

Treatment recommendations changed in recent years and now differ by sex. Women are treated with a seven-day course of oral metronidazole rather than the older single-dose approach, since research showed the longer course clears the infection more reliably in women. The CDC's updated STI treatment guidelines reflect this change. A single dose of tinidazole is an effective alternative. Because trichomoniasis is sexually transmitted, your partner needs treatment too, and you should both avoid sex until treatment is complete. 

Mycoplasma Genitalium ("Mgen") 

Mycoplasma genitalium is a lesser-known but increasingly important sexually transmitted bacterium. It wasn't identified until decades after chlamydia and gonorrhea, and reliable FDA-approved testing has only existed since 2019. Many people have never heard of it, even though it's linked to cervicitis, pelvic inflammatory disease, and pregnancy complications. 

Symptoms 

• Abnormal discharge 
• Pelvic pain 
• Bleeding between periods or after sex 
• Pain with intercourse 

Mgen often causes no symptoms, but that doesn't mean everyone should be screened for it. Because it's difficult to treat and antibiotic resistance is a growing concern, testing is generally reserved for people with symptoms or a partner who's tested positive. Screening everyone regardless of symptoms would mean more unnecessary antibiotic use without a clear benefit. 

Diagnosis 

Mgen requires a specific molecular (NAAT) test and won't show up on a standard STI panel unless it's specifically included. 

Treatment 

Treatment is more involved than most vaginal infections because Mgen has developed significant antibiotic resistance worldwide. The current approach uses two steps: doxycycline first to reduce the bacterial load, then a second antibiotic chosen based on resistance testing when it's available. Azithromycin is used for resistance-sensitive strains, and moxifloxacin for resistant ones. When resistance testing isn't available, doxycycline followed by moxifloxacin is the default. Because resistance develops so commonly, a follow-up test of cure is often recommended. 

A Note on Other Sexually Transmitted Infections 

Vaginal symptoms aren't the only reason to think about sexual health. Several important STIs cause no symptoms at all, which is exactly why routine screening matters even when you feel completely fine. 

Chlamydia and gonorrhea are common bacterial infections that, left untreated, can lead to pelvic inflammatory disease and affect future fertility. HIV and syphilis are both effectively managed or treated when caught early, but can have serious long-term consequences when missed, and syphilis rates have been rising in recent years. HPV (human papillomavirus) is extremely common, is the primary cause of cervical cancer, and is preventable through vaccination as well as detectable early through routine cervical cancer screening. 

Current screening guidelines include: 

• Chlamydia and gonorrhea: all sexually active women 24 and under, and women 25 and older with risk factors 
• HIV: at least once for everyone 13 to 65, and with every pregnancy 
• Syphilis: anyone at increased risk, and universally during pregnancy 
• HPV and cervical cancer: a routine schedule starting at age 21 

Since so many of these infections are silent, routine STI testing, not just symptom-based testing, is the only reliable way to catch them early. 

Come Get Answers, Not Just Relief 

Whether you're dealing with symptoms right now or it's simply been a while since your last screening, our team at FPA Women's Health offers judgment-free, thorough vaginal infection screening and treatment. Most of the conditions above are quickly diagnosed with a simple exam or test, and quickly treated once identified, whether in person or through telehealth for a follow-up or prescription. 

If you're dealing with severe pain, fever, or heavy bleeding, that's not something to wait out. Call our 24-hour Nurse Advice Line at (877) 883-7264. 

Frequently Asked Questions 

How can I tell a yeast infection apart from bacterial vaginosis? 

The discharge is usually the biggest clue. A yeast infection tends to cause thick, white discharge with intense itching and little odor. BV usually causes thinner, grayish discharge with a noticeable odor and less itching. Symptoms can overlap, though, so testing is the only way to know for certain, and it changes what treatment you need. 

Can a vaginal infection go away without treatment? 

Sometimes, but it's not something to count on. BV in particular can resolve on its own but frequently comes back or leads to complications if left untreated. Getting tested and treated is the more reliable path, especially since some infections raise your risk for other STIs if they linger. 

Do I need to tell my partner if I test positive for trichomoniasis or Mgen? 

Yes. Both are sexually transmitted, and your partner needs treatment too, even if they have no symptoms. You should avoid sex until you've both completed treatment so you don't pass the infection back and forth. 

Why haven't I heard of Mycoplasma genitalium before? 

It's a newer discovery in the world of STIs. Reliable, FDA-approved testing has only been available since 2019, so it hasn't been part of routine screening panels for as long as chlamydia or gonorrhea. That's changing as more providers become aware of it. 

Is it normal to have a vaginal infection with no symptoms at all? 

Yes, and it's more common than people expect. Trichomoniasis, Mgen, BV, and even non-albicans yeast infections can all be present without any noticeable symptoms. This is a major reason routine screening matters, not just testing when something feels wrong. 

How often should I get screened if I don't have symptoms? 

It depends on your age and risk factors. Sexually active women 24 and under should be screened for chlamydia and gonorrhea at least annually, and women 25 and older should be screened if they have risk factors like a new or multiple partners. Talk with your provider about a schedule that fits your situation.