A yeast infection is the overgrowth of the naturally occurring fungal species, candida, and can occur for a variety of reasons. Yeast infections often present in the mouth or vagina, and on occasion can grow under the foreskin of uncircumcised penises. These are quite common in women, with 3 out of 4 reporting at least one yeast infection in their lifetime, usually in women of reproductive age.

Common Symptoms and Causes

Vaginal yeast infections can be quite bothersome, often causing symptoms that may feel similar to some sexually transmitted infections (STIs), despite not being considered as such. You may have a vaginal yeast infection if you are experiencing:

• Thick, white, “cottage cheese” discharge,
• Itching or burning feeling in the vaginal area,
• Redness or swelling around the vulva and vagina,
• Pain during sex,
• Pain or burning sensation while urinating,
• Small cuts or cracks on the skin of the vulva.

Normally, candida overgrowth is the result of non-sexual behavior, such as douching, tight and non-breathable clothing, wearing wet clothes for too long, scented feminine products, soaps, or sprays, and silicone-based lubricants. Additionally, diabetics may be more likely to get a yeast infection if their blood sugar levels are not managed properly.

Generally speaking, yeast infections are not the result of sex, but they could be activated or worsened by sexual activity. Changes in the vaginal pH from semen, a partner’s pH, condoms, spermicides, lubricants, or other sexual aids can cause this overgrowth of the candida fungus.

If an existing yeast infection is mild or unnoticeable before sexual activity, penetrative sex could irritate the already inflamed vaginal lining. This would then make it seem as though a yeast infection resulted from sex. Additionally, if a partner has an oral yeast infection, then oral sex may “spread” the candida fungus to the vagina, resulting in a vaginal yeast infection – although this is very unlikely.

Treatment and Prevention

Common treatments for yeast infections include antifungals such as fluconazole, miconazole (Monistat), or terconazole. A yeast infection is unlikely to go away on its own, so it is important to seek treatment when you notice any of the symptoms.

Additionally, it is advised not to engage in sexual activity while on the prescribed antifungals. For one, sexual activity could further irritate the vaginal area, and for two, the antifungals prescribed may weaken contraceptives like condoms or diaphragms.

To prevent vaginal yeast infections, it’s important to try to avoid douching; wearing tight, wet, or unbreathable clothing for too long; using scented pads, tampons, or soaps; or using a silicone-based lubricant (try a water-based lubricant instead).

Key Points

• Yeast infections are the result of the candida fungus growing too fast or too much for the body to keep up with.
• Infections are normally caused by non-sexual hygiene behaviors, such as wearing tight clothing and using scented feminine products or soaps, but they can stem from sexual activity-related choices like using certain condoms or lube or pH imbalances caused by a partner’s skin or semen.
• It’s important to avoid the things that may cause vaginal yeast infections to prevent them from occurring.
• If you believe you have a vaginal yeast infection, it’s important to speak with a health provider so they can help you find the right course of treatment.

Resources

• InformedHealth.org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. Overview: Vaginal yeast infection (thrush) [Updated 2022 Apr 4]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK543220
• Jeanmonod R, Chippa V, Jeanmonod D. Vaginal Candidiasis. [Updated 2024 Feb 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459317/
• Nyirjesy, P., Brookhart, C., Lazenby, G., Schwebke, J., & Sobel, J. D. (2022). Vulvovaginal candidiasis: A review of the evidence for the 2021 Centers for Disease Control and prevention of sexually transmitted infections treatment guidelines. Clinical Infectious Diseases, 74(Supplement_2). https://doi.org/10.1093/cid/ciab1057