A yeast infection can cause white patches in the mouth, flaking or crusting of the skin, and changes in genital discharge. Symptoms can vary depending on the location and severity of the infection.

A yeast infection occurs when fungi grow excessively in the body. This is particularly common in moist areas with less exposure, such as the mouth, vagina, or feet.

Many common types of fungi occur naturally on the skin and in other areas of the body with no ill effect. Yeast infections are commonly due to overgrowth infection of fungi from the Candida species.

In this article, we describe how a yeast infection visibly affects the body. We also look at other symptoms, treatments, and more.

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A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

Yeast infections are not considered sexually transmitted infections (STIs). However, it is possible for a person to develop a yeast infection after having oral, anal, or vaginal sex with someone who has the condition, especially if they are especially susceptible.

Vaginal yeast infection

A vaginal yeast infection, or thrush, typically causes a white discharge that is the texture of cottage cheese.

Other symptoms of a vaginal yeast infection include:

These infections are common, with up to 75% of females having at least one diagnosed in their lifetimes.

Penile yeast infection

Yeast infections can affect the penis, but this is less common. The symptoms tend to develop on the underside of the penis and include:

Oral thrush occurs when yeast grows excessively in the mouth or throat. Typically, a person develops white patches on the tongue, cheeks, back of the throat, or roof of the mouth.

  • soreness
  • pain while eating or drinking
  • a cotton-like feeling in the mouth
  • cracked skin at the corners of the mouth
  • a loss of taste

Most healthy adults do not develop oral thrush, but yeast infections in the mouth or esophagus are common in people with weakened immune systems.

Wearing dentures, smoking, and having dry mouth also elevate the risk of developing oral thrush.

The appearance of a yeast infection on the skin depends on the location, but this type of infection often causes patches of inflammation. These can vary in shape and size. Sometimes, these patches itch, flake, or develop crusts, and pustules may appear around the edges.

A yeast infection can occur anywhere on the skin, but it is common as a secondary infection of intertrigo–which is irritation in skin folds such as:

  • under the breasts
  • under the arms
  • in the groin
  • under or in the buttocks
  • in the navel
  • on the scalp
  • between the fingers and toes

If a yeast infection occurs on the scalp, it can cause crusty lesions that can lead to hair loss. Yeast infections can also cause diaper rash in babies.

Yeast infections can develop beneath the nails. An infected nail may turn white or yellow and start to separate from the nail bed.

When a yeast infection occurs under the nails, a person may experience:

In small amounts, Candida fungi are not harmful. Many people have yeast on their skin and in their bodies. Other types of microbe, such as bacteria, help keep Candida from growing excessively.

However, certain factors can disrupt the body’s ability to keep Candida under control, such as:

  • Antibiotics: Because antibiotics kill bacteria, the result may be that Candida fungi grow unchecked.
  • Hormonal contraceptives: People who take hormonal birth control that contains estrogen are more likely to develop yeast infections.
  • Pregnancy: Similarly, the hormonal changes during pregnancy increase the chances of developing yeast infections.
  • A weak immune system: Young babies and people with immune disorders or conditions such as HIV may be more susceptible to yeast infections.
  • Medications: Some medications and treatments, including steroids, immunosuppressants, and chemotherapy also weaken the immune system.
  • Diabetes: Sugar helps yeast grow, so people with frequently high blood sugar levels, such as in diabetes, are more likely to develop candidiasis.

Vaginal douches and sprays may also increase the risk of developing a vaginal yeast infection.

A person should talk with a doctor if they notice symptoms of yeast infection. Receiving the right treatment for any infection is important, and correctly identifying the type of infection is the first step.

It is important to speak with a doctor first because the symptoms of a vaginal yeast infection are similar to those of bacterial vaginosis and some STIs. These issues do not respond to yeast infection treatments. They require different approaches and can cause serious health complications if a person does not receive the necessary care.

The treatment for a yeast infection varies, depending on the infection’s location and severity. For mild, occasional infections, a person can try over-the-counter options, such as topical creams, nail treatments, or vaginal suppositories.

A person may need prescription antifungal medication for more severe or reoccurring infections. However, frequently using antifungal medicine unnecessarily may reduce its effectiveness in the future.

Pregnant people should not take the antifungal medication fluconazole (Diflucan), as it may cause birth defects, the Office on Women’s Health report.

Yeast infections often cause abnormal genital discharge and white patches to form in the mouth or in skin folds.

A doctor can confirm the infection and recommend the best treatment, depending on the severity and the part of the body involved.