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What causes yeast infection?

Learn what causes yeast infection and what may put you at greater risk

Key takeaways

  • Vaginal yeast infections, caused by an overgrowth of Candida albicans, are common, affecting nearly 70% of women at least once in their lifetime, with symptoms including itching, burning, and thick white discharge.

  • Factors contributing to yeast infections include antibiotic use, uncontrolled diabetes, hormonal changes during pregnancy, poor hygiene, tight clothing, high sugar diets, oral contraceptives, weakened immune systems, douching, excessive sweating, and stress.

  • Yeast infections are not considered sexually transmitted infections but can be transferred through sexual contact; they can be treated with over-the-counter or prescription medications, though lifestyle changes may also help prevent recurrence.

  • It’s important to accurately diagnose a yeast infection, as symptoms can mimic other conditions; consulting a healthcare provider is advised for proper treatment and to explore options like over-the-counter antifungals or prescription medication.

Yeast infections can be uncomfortable with persistent, bothersome symptoms. However, these types of infections are quite common, with almost 70% of women experiencing a vaginal yeast infection at least once in their lifetime. A small percentage of women who experience a vaginal yeast infection will experience recurrent yeast infections, which can occur multiple times throughout the year. 

But how do you get yeast infections, and why are they so common? In this article, we’ll go over the different yeast infection causes and risk factors, many of which can be prevented. 

What is a vaginal yeast infection?

A vaginal yeast infection, also known as vaginal candidiasis, is a common condition that affects many women. It can develop when there is an overgrowth of Candida albicans, a fungus that normally lives on the skin and inside the body, including the vagina.

When the balance between the good and bad bacteria in the vagina gets thrown off due to factors like stress or hormonal changes, an imbalance in vaginal flora can occur that allows Candida albicans to grow out of control. This imbalance can lead to a yeast infection.

A vaginal yeast infection looks like a thick white discharge that may be accompanied by itching and burning. Some women experience pain during urination or sexual intercourse when they have a yeast infection.

According to The Office on Women’s Health (OWH), Yeast infections are not considered STIs because they do not spread from one person to another. However, it’s possible to get a yeast infection after having sex because semen can alter the vaginal environment and allow the fungus to grow quickly.

Vaginal yeast infection symptoms

Symptoms of a vaginal yeast infection include itching, soreness, burning, swelling, redness of the vulva, and white discharge from the vagina. These symptoms are usually present during the first few days after the infection begins.

If left untreated, this condition can cause pain during sex and urination as well as swelling of the clitoris and vagina, which can make sex difficult or impossible to perform.

The following are possible symptoms of a vaginal yeast infection:

  • Itching, irritation, or burning in the vagina and vulva (the outer part of the female genitals)
  • Pain or discomfort during sexual intercourse
  • A burning sensation or discomfort while urinating
  • Thick, white, and odorless discharge that looks like cottage cheese
  • Watery discharge from the vagina
  • Vulvar swelling and redness
  • A rash in or around the vagina

Regardless of what symptoms are present and how uncomfortable symptoms can be, vaginal yeast infections are not a sign of a woman’s uncleanliness. In fact, most women experience some type of vaginal discharge at some point in their lives—and that discharge is usually perfectly normal.

What can be mistaken for a yeast infection?

Vaginal yeast infections are common, but other conditions can mimic their symptoms. If someone thinks they have a yeast infection, it’s important to see a doctor for an accurate diagnosis. Some of the conditions that can look like a vaginal yeast infection include:

  • Bacterial vaginosis (BV), a bacterial infection that can cause inflammation and discharge from the vagina
  • Sexually transmitted diseases (STDs), such as chlamydia and gonorrhea
  • Infection of the uterus (endometritis) 
  • Urinary tract infections (UTIs), which are more common in women than men and cause burning when urinating as well as frequent urges to pee

What causes yeast infection?

The main cause of vaginal yeast infections is an overgrowth of a fungus called Candida albicans. The fungus can normally be found within the body, including the vagina, skin, mouth, and digestive tract. In fact, according to the CDC, one out of five women have Candida in the vagina without any symptoms. However, if the fungus grows out of control, symptoms of an infection can occur, such as itching and burning.

The following are some things that can increase the risk of developing a yeast infection:

  1. Antibiotics. These medications can kill bacteria that normally keep the Candida albicans fungus in check, which can lead to overgrowth and a vaginal yeast infection.
  2. Uncontrolled Diabetes. A woman with diabetes has an increased risk of developing a yeast infection because people with high blood sugar levels have excess sugar that can act as a fuel source for the growth of the fungus.
  3. Pregnancy. Women who are pregnant may be at a higher risk for developing a yeast infection because their bodies undergo changes in hormone levels. Increased estrogen levels can disrupt the normal pH balance in the vagina of pregnant women, which can create a favorable environment for yeast to grow.
  4. Poor Hygiene. Wiping from back to front after using the bathroom can spread harmful bacteria and yeast from the anus to the vaginal area, which can lead to a yeast infection.
  5. Tight Clothes. Wearing tight pants, underwear, or pantyhose all day long can increase the risk of vaginal yeast infections. Tight clothing can trap heat and moisture against the skin, which can promote the overgrowth of yeast.
  6. Poor Diet and Nutrition. Eating a diet high in sugar can increase the risk of developing a fungal infection, as excess sugar in the urine can act as a food source for Candida albicans in the vagina to grow quickly.
  7. Taking oral contraceptives. Some women who take oral contraceptives are more likely to develop yeast infections. The hormones in birth control pills may cause changes in the pH balance of the vagina, making it easier for Candida albicans fungus to grow.
  8. Weakened immune system. With a weakened immune system, it can be harder for the body to fight off an overgrowth of the Candida albicans fungus. People with a weakened immune system may also be taking steroids or antibiotics that can disrupt the balance of yeast and bacteria in the vagina.
  9. Using a douche. Douching can increase the risk of developing a yeast infection by disrupting the natural balance of the vaginal flora. Using a douche can flush out the healthy bacteria in the vagina and cause a pH imbalance. 
  10. Excessive sweating. Excessive sweating around the vagina can create a moist, warm environment for fungus to grow, which in turn may cause a yeast infection to develop. This may be a particular concern for women who live in hot, humid conditions. 
  11. Stress. Stress can weaken the functions of the body’s immune system, making you more susceptible to infections like yeast infections.

Potential yeast infection causes and risk factors are numerous, leading to yeast infections that can happen more often than we would like. However, yeast infections can be treated and managed through lifestyle changes and various treatment options.

Are yeast infections contagious?

A vaginal yeast infection is not usually contagious or considered a sexually transmitted infection. However, it is caused by a type of fungus that can be passed from person to person. Therefore, a yeast infection can be passed through sexual contact with someone who has the infection on their genitals.

Yeast infection treatment

A vaginal yeast infection is treatable with over-the-counter medications, but it can be difficult to decide which one will work best. If you’re unsure of which product to choose, consult a doctor or pharmacist for medical advice before buying any over-the-counter medicines.

A mild yeast infection can resolve on its own within two to three days, but a more severe infection can persist for one to two weeks or longer. If you experience severe yeast infection symptoms, consider visiting a healthcare provider for the best treatment options. For example, you may want to see a healthcare professional if the area around the vagina is red or inflamed. A healthcare provider can perform a physical exam as needed, assess symptoms, and differentiate between the types of vaginal infections, such as bacterial vaginosis or trichomoniasis.

Is it safe to take OTC medications for vaginal yeast infection?

If you’re wondering whether it’s safe to use an OTC or prescription antifungal medication for a vaginal yeast infection, the answer is yes.

There are many over-the-counter (OTC) and prescription medications available that are designed to treat yeast infections. Many of these medications work by creating an inhospitable environment for the yeast, while others work by killing off the yeast itself.

The most common OTC medications used to treat vaginal yeast infections include Monistat (miconazole) and Gyne-Lotrimin 3 (clotrimazole). You can get these at any pharmacy without a prescription. Monistat also comes in a gel form that you can apply directly to the vulva or vagina.

Some yeast infections may be treated at home with natural or herbal remedies and products, such as Greek yogurt and tea tree oil. However, more research is needed on home remedies. It’s best to consult a healthcare provider for more information before self-treating a yeast infection, especially if you don’t experience them often. 

Certain prescription medications, including Diflucan (fluconazole) and Brexafemme (ibrexafungerp), are effective treatments for vaginal yeast infections. These medications need to be prescribed by a doctor or healthcare provider and will often come in pill form—though there are some prescription antifungal creams available as well.

RELATED: Vagisil vs. Monistat Monistat vs. Diflucan How much is fluconazole without insurance?

The bottom line

Vaginal yeast infections are a common problem, and they can be a real pain. But they’re relatively mild and easy to treat.

It’s important to identify the potential causes and risk factors of a vaginal yeast infection, what the symptoms are and when to see a doctor, and how to treat the infection using over-the-counter medications or prescription medications.

If you still have questions about vaginal yeast infections, we encourage you to consult a healthcare provider to ensure you’re getting the right treatment for your symptoms.