A vaginal yeast infection is a fungal infection. It causes irritation, discharge and itching of the vagina and the vulva. Vaginal yeast infection also is called vaginal candidiasis.

Vaginal yeast infection affects most people assigned female at birth at some point in life. Many have at least two infections.

People who don't have sex can get a vaginal yeast infection. So it isn't though of as a sexually transmitted infection. But you can get vaginal yeast infections through sex.

There's a higher risk of vaginal yeast infection when you start having sex. And some vaginal yeast infections may be linked to sexual contact between the mouth and genital area, called oral-genital sex.

Medicines can treat vaginal yeast infections. Yeast infections that happen four times or more a year may need a longer treatment course and a plan to prevent them.

Yeast infection symptoms range from mild to moderate. They may include:

• Itching and irritation in the vagina and tissues at the vaginal opening, called the vulva.
• A burning feeling, mainly during intercourse or while urinating.
• Redness and swelling of the vulva. Redness may be harder to see on Black or brown skin than on white skin.
• Vaginal pain and soreness.
• Thick, white vaginal shedding of fluid and cells, called discharge, with little or no odor. The discharge looks like cottage cheese.

Complicated yeast infection

You might have a complicated yeast infection if:

• You have severe symptoms, such as a lot of redness, swelling and itching that leads to tears, cracks or sores in the vagina.
• You have four or more yeast infections in a year.
• Your infection is caused by a less common type of fungus.
• You're pregnant.
• You have diabetes that isn't well-managed.
• Your immune system is weakened because of certain medicines or conditions such as HIV infection.

When to see a doctor

Make an appointment with your healthcare professional if:

• This is the first time you've had symptoms of a yeast infection.
• You're not sure whether you have a yeast infection.
• Your symptoms don't go away after you treat them with antifungal vaginal creams or suppositories that you can get without a prescription.
• You have other symptoms.

The fungus Candida albicans causes most vaginal yeast infections.

Most often, the vagina has a balance of yeast, including candida, and bacteria. Certain bacteria called lactobacillus work to prevent too much yeast.

But some factors can affect the balance. Too much candida or the fungus growing deeper into vaginal cells causes symptoms of a yeast infection.

Too much yeast can result from:

• Antibiotic use.
• Pregnancy.
• Diabetes that isn't well-managed.
• A weakened immune system.
• Use of birth control pills or hormone therapy that raises levels of the hormone estrogen.

Candida albicans is the most common type of fungus to cause yeast infections. When other types of candida fungus cause yeast infections, they can be harder to treat.

Factors that raise the risk of getting a yeast infection include:

• Antibiotic use. Yeast infections are common in people who take antibiotics. Broad-spectrum antibiotics kill a range of bacteria. They also kill healthy bacteria in the vagina. This can lead to too much yeast.
• Raised estrogen levels. Yeast infections are more common in people with higher estrogen levels. Pregnancy, birth control pills and hormone therapy can raise estrogen levels.
• Diabetes that isn't well-managed. People with poorly managed blood sugar are at greater risk of yeast infections than are people with well-managed blood sugar.
• Weakened immune system. People with lowered immunity are more likely to get yeast infections. Lower immunity might be from corticosteroid therapy or HIV infection or other diseases that suppress the immune system.

To lower your risk of vaginal yeast infections, wear underwear that has a cotton crotch and doesn't fit too tightly.

Also, these tips might help prevent a yeast infection:

• Do not wear tight pantyhose, underwear or jeans.
• Do not douche. This removes some of the good germs in the vagina that protect from infection.
• Do not use scented products in the vaginal area. For instance, don't use scented bubble bath, soap, menstrual pads and tampons.
• Do not use hot tubs or take hot baths.
• Do not use antibiotics you don't need. For instance, don't take antibiotics for colds or other viral infections.
• Do not stay in wet clothes, such as swimsuits and workout clothes, for longer than needed.

To diagnose a yeast infection, your healthcare professional may:

• Ask about your medical history. This might include past vaginal infections or sexually transmitted infections.
• Do a pelvic exam. This involves looking at your outer genitals for signs of infection. Then your healthcare professional puts an instrument called a speculum into your vagina. The speculum holds the vaginal walls open so the vagina and cervix are easy to see. The cervix is the lower, narrower part of the uterus.
• Test vaginal fluids. Lab tests of vaginal fluid can look for yeast or find the type of fungus causing the yeast infection. Knowing the fungus can help your healthcare professional suggest treatment.

Treatment for yeast infections depends on how bad the infections are and how often they happen.

If you have mild to moderate symptoms and don't get infections often, treatment options include:

• Short-course vaginal therapy. Using an antifungal medicine for 3 to 7 days most often clears a yeast infection. Antifungal medicines come in the form of creams, ointments, tablets and small objects you put into your vagina, called suppositories. They include miconazole (Monistat 3) and terconazole. You can get these medicines with or without a prescription.
• One dose of medicine taken by mouth. Your healthcare professional might prescribe one dose of fluconazole (Diflucan). To manage severe symptoms, you might take two doses three days apart. Oral medicine is not used often in pregnancy, especially in the first trimester.

The U.S. Food and Drug Administration recently approved two medicines to treat vaginal yeast infections. One is oteseconazole (Vivjoa), taken by mouth. This medicine is only for people who can't get pregnant and who have infections that keep coming back.

The other medicine is ibrexafungerp (Brexafemme). This also is taken by mouth. Studies show that these medicines might work for vaginal yeast infections that don't respond to other treatments.

See your healthcare professional again if treatment doesn't clear your symptoms or if your symptoms return within two months.

Treatment for yeast infections that have severe symptoms or that happen often might include:

• Long-course vaginal therapy. You use an antifungal medicine daily for up to two weeks. Then you take it once a week for six months.
• More than one dose of medicine taken by mouth. You take 2 to 3 doses of an antifungal medicine by mouth instead of having vaginal therapy. But this therapy isn't for pregnant people.
• Boric acid therapy. A capsule that has boric acid is put into your vagina. This medicine may be fatal if taken by mouth. It only treats candida fungus that doesn't respond to other treatments. It is not recommended for use in pregnancy.

No alternative medicine therapies have been proved to treat vaginal yeast infections. Some alternative therapies may give some relief when taken with what your healthcare professional suggests.

Talk to your healthcare professional about what alternative therapies for vaginal yeast infection may be safe for you.

If you've been treated for a yeast infection in the past, your healthcare professional may prescribe a treatment over the phone without seeing you. If not, you likely need to see your primary care professional or gynecologist.

What you can do

Don't use tampons or douche before your appointment.

Make a list of:

• Your symptoms and when they began.
• Other medical conditions you have.
• All medicines, vitamins or supplements you take, including doses.
• Questions to ask your healthcare professional.

Some questions to ask about vaginal yeast infections include:

• What can I do if my symptoms return after treatment?
• How can I prevent yeast infections?
• What symptoms should I watch out for?

Be sure to ask all the questions you have.

What to expect from your doctor

Your healthcare professional is likely to ask you questions, such as:

• Do you notice a strong vaginal odor?
• Have you ever been treated for a vaginal infection?
• Have you tried products you can get without a prescription to treat your condition?
• Have you recently taken antibiotics?
• Are you sexually active?
• Are you pregnant?
• Do you use scented soap or bubble bath?
• Do you douche or use feminine hygiene spray?