The appearance of a yeast infection, or candidiasis, depends on its location. It can cause white patches in the mouth, flaking or crusting of the skin, and changes in genital discharge, which may look like cottage cheese.

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

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.

Often, yeast infections are caused by fungi from the Candida species — and according to the Centers for Disease Control and Prevention (CDC), Candida albicans is the type most likely to overgrow and cause an infection.

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

Other symptoms of a vaginal yeast infection include:

  • painful urination
  • soreness around the vagina
  • inflammation and itchiness of the vagina and vulva
  • pain during sex

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

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

  • scaling
  • inflamed patches of skin
  • a painful rash

A yeast infection can also cause inflammation near the head of the penis. This issue is called balanitis.

A person with balanitis may experience burning or itching and yellow or white discharge. In some people, the inflammation spreads to the shaft and the area under the foreskin.

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.

Around 15% of males who have unprotected sex with females experiencing yeast infections develop the infection themselves.

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.

Other symptoms of oral thrush include:

  • 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 is most likely to develop in 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 body. 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 if a person frequently has high blood sugar levels, they are more likely to develop candidiasis.

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

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.

However, it is important to speak with a pharmacist or 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.

Also, frequently using antifungal medicine unnecessarily may reduce how effective it is in the future.

For more severe or reoccurring infections, a person may need prescription antifungal medication.

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

Some home care strategies may help reduce yeast infection symptoms or prevent the issue from coming back.

Probiotic yogurt may help reduce the amount of yeast in the body. A 2013 pilot study involving 24 women showed that eating 8 ounces of probiotic yogurt per day reduced the presence of Candida in some cases.

However, this was a small study with mixed results. Also, the women had HIV, so their health responses may not reflect those of the general population.

Addressing the cause of the infection is important, especially if the infection keeps coming back. A person may benefit from:

  • using a condom during sex
  • avoiding the overuse of antibiotics
  • switching to a different method of birth control
  • better managing underlying conditions, such as diabetes

A person should talk to a doctor if they notice symptoms of a yeast infection.

It is important to receive the right treatment for any infection, and correctly identifying the type of infection is the first step.

Yeast infections often cause changes to genital discharge and 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.