Yeast infections aren't contagious - here's what causes them and how to avoid getting one

• Yeast infections are rarely contagious and are commonly caused by an overgrowth of yeast.
• Though they aren't normally contagious, yeast infections can cause irritation and discomfort during sex, so its recommended to avoid sexual activity if you have one.
• Practicing good hygiene, among several other practices, is key to preventing yeast infections from developing.

Yeast infections aren't typically contagious, but they are potentially transmitted in some situations. They can develop in the mouth, esophagus, genitals, and skin.

A yeast infection, clinically called Candidiasis, is caused by an overgrowth of a naturally-occuring yeast called Candida. Normally, Candida lives harmoniously on the body and is generally harmless.

However, when the body's ecosystem of natural bacteria is disrupted, Candida populations can overgrow and transition from being harmless to causing disease, says Marwan Mikheal Azar, MD, assistant professor of internal medicine, and infectious diseases, at Yale School of Medicine.

When the infection invades the bloodstream, it is potentially life-threatening for people with weakened immune systems, such as those undergoing chemotherapy or organ transplants, if not immediately treated.

Other species of yeast can also cause infections, but this article focuses on Candida in particular and will discuss the types of infections it can cause, how they develop, and how to minimize the risk of developing them.

Can you contract a yeast infection from sexual contact?

In general, contracting a yeast infection through sexual activity is very unlikely

"Candida infections are generally not transmitted from person to person, so physical contact, including any form of sex, is usually not a problem," says Azar. This means that kissing or having sex might not result in the transmission of a yeast infections if you or your partner has one. Mayo Clinic also states that yeast infections aren't sexually transmitted.

On the other hand, according to the US Centers for Disease Control and Prevention (CDC), vulvovaginal candidiasis is "not usually acquired" through sex. The Office on Women's Health also states that it's possible to transmit yeast infections through vaginal, oral, or anal sex, with a lower infection risk for people with penises.

Therefore, to err on the side of caution, if you or your partner has a yeast infection, it's best to avoid sex until the infection is fully treated. Sexual intercourse can prolong the symptoms, irritate the genitals to the point of pain, or cause tiny cuts that increase the risk of STIs.

Symptoms of yeast infections

When you have an impaired immune system or the levels of healthy bacteria in your body changes, Candida has the opportunity to multiply and cause disease.

Yeast infections can affect various parts of the body and manifest different symptoms.

• Mouth: Oral candidiasis, also known as oral thrush, usually manifests as creamy white lesions inside the mouth, soreness that causes swallowing difficulties, and cracking at the corners of the mouth. It is most common among babies younger than 6 months old.
• Esophagus: People with esophageal candidiasis often experience difficulty or pain when swallowing and chest pain behind the breast bone.
• Breast: Nursing mothers may experience a sharp pain deep into the breast, sore nipples, and a red, flaky rash on the areola if they develop a yeast infection of the breast. It can be passed during breastfeeding, which may occur when either the baby or mother has taken antibiotics.
• Vagina: Itching, irritation, soreness, or rashes in and around the vagina are some of the symptoms of a vaginal yeast infection, also known as vulvovaginal candidiasis. Vaginal discharge with a cottage cheese appearance and a burning sensation during urination or sexual intercourse are common signs as well.
• Penis: Candidal balanitis is a yeast infection causing inflammation in the head of the penis. Some symptoms include redness, pain, and a foul-smelling discharge from under the foreskin.
• Skin: A yeast infection on the skin, or cutaneous candidiasis, can affect any skin on the body. However, it's more common in the armpits and the groin, characterized by redness and thickening of the skin.
• Bloodstream: When the yeast infection is in your bloodstream (also called candidemia) appears like any other bloodstream infection with symptoms like chills, shivering, fever, or severe sepsis. The best way to diagnose it is by having a blood culture, a laboratory test that detects bacteria or fungi in your blood.

If you experience these symptoms, seek medical attention for proper diagnosis and treatment. "Your doctor will also have to determine the underlying trigger so that it can be addressed, preventing recurrence of the disease," says Azar.

How could you get a yeast infection?

The overgrowth of Candida is the only cause of yeast infections, but some factors increase the risk, such as:

• Weakened immune system: People undergoing chemotherapy, as well as those with medical conditions that suppress the immune system like HIV/AIDS and diabetes, are more likely to get a yeast infection. Individuals who need dialysis or recently had an organ transplant are also at a higher risk.
• Injection drug use: It's uncommon, but people who inject illegal drugs are at risk for yeast infection in the bloodstream due to unsafe injection practices like using old syringes, dirty needles, and unclean cotton.
• Medications: Steroids, antibiotics, and birth control pills can make yeast thrive. They throw off the vagina's chemical balance and potentially result in yeast infections.
• Heart failure disease: People with heart failure often experience prolonged hospitalization, undergo surgeries, and are treated with various antibiotics, which make them susceptible to yeast infections. Catheters can easily transmit bacteria and fungi, which include the Candida species.

Sometimes pets can develop yeast infections, often in their ears and skin. "Candida does not generally transmit from pets to humans," says Azar. Though dogs do transmit certain viral, fungal, and bacterial diseases to humans, they generally do not transmit Candida infections.

How can you avoid getting a yeast infection?

"To minimize the risk of getting yeast infections, you must minimize the risk factors that predispose to yeast infections," says Azar.

In addition to practicing proper hygiene, you can do the following to reduce the likelihood of getting a yeast infection:

• Follow good dental hygiene practices to prevent oral thrush (aka a yeast infection of the mouth). If you wear dentures, clean them regularly to reduce the likelihood of denture stomatitis, an oral yeast infection.
• Avoid douches, scented menstrual products, feminine deodorants, and water-based sexual lubricants in the vagina.
• Keep your skin dry to avoid cutaneous candidiasis. Wear breathable materials and regularly change underwear. For infants, make sure to use breathable diapers.
• Watch out for a skin yeast infection if you have excess fat on your body, because the excessive moisture in the skin folds is a risk factor.
• Quit smoking, which is a risk factor for both oral and esophageal candidiasis.
• Manage the medical conditions that put you at risk of yeast infections, such as diabetes.
• Be mindful of antibiotic use as it may kill normal bacteria that keep Candida in check.

Insider's takeaway

Yeast infections can develop in various parts of the body, which include the mouth, esophagus, genitals, skin, and bloodstream. They are primarily caused by an overgrowth of Candida, which is a type of yeast. Having sex with an untreated yeast infection is ill-advised and can prolong the symptoms.

There are many ways to minimize the risk of getting a yeast infection, such as regularly changing underwear, quitting smoking, and following good dental hygiene practices. Recurrent yeast infections can be a sign of an underlying health condition, so it's crucial to seek medical attention to prevent recurrences, says Azar.

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