Candida infection, also known as candidiasis, is a fungal infection that happens when yeast that normally lives peacefully on your body decides to multiply out of control. This common condition can affect your mouth, skin, vagina, and in serious cases, even your internal organs. While most Candida infections are uncomfortable rather than dangerous, they still need proper attention and treatment to prevent complications.

What Is Candida Infection?

Candida is a type of yeast that naturally lives in and on your body. Think of it as one of many tiny organisms that call your body home, usually causing no trouble at all. This yeast can be found on your skin, in your mouth, in your digestive tract, and in the vagina. Under normal circumstances, healthy bacteria in your body keep Candida in check, maintaining a natural balance.^[1]

However, when something disrupts this delicate balance, Candida can grow out of control and cause an infection called candidiasis. The infection appears in different forms depending on where it occurs in your body. When it affects your mouth and throat, it’s called thrush. When it develops in the vagina, it’s known as a vaginal yeast infection. Skin infections typically occur in warm, moist folds of the body, such as under the breasts, in the armpits, or in the diaper area of infants.^[1]

The most common species responsible for these infections is Candida albicans, though other types of Candida can also cause problems. More than 90% of invasive disease is caused by five main species: C. albicans, C. glabrata, C. tropicalis, C. parapsilosis, and C. krusei. Each has unique characteristics, but infections from all of them are generally referred to as candidiasis.^[2]

Epidemiology: How Common Is Candida Infection?

Candida infections are remarkably common, affecting millions of people worldwide every year. Vaginal yeast infections alone affect about 75% of women at some point in their lives, making them one of the most frequent fungal infections people experience. Of these women, approximately 40% to 45% will have at least two episodes during their lifetime.^[7]

The infection doesn’t discriminate by age or gender, though certain groups face higher risks. Vaginal candidiasis naturally affects only women and people assigned female at birth. Oral thrush is particularly common in newborn babies, older adults, and individuals with weakened immune systems. People with diabetes or those undergoing cancer treatment are also more susceptible to developing Candida infections.^[8]

In healthcare settings, Candida represents a significant concern. It’s one of the most common causes of healthcare-associated infections in the United States. When Candida enters the bloodstream—a condition called candidemia—it becomes a medical emergency. About one in four patients with invasive bloodstream Candida infections may die from the condition, highlighting how serious these infections can become when they spread beyond the skin or mucous membranes.^[2]

The distribution of Candida infections varies by location and type. Diaper rash caused by Candida is extremely common in infants. Among hospitalized patients, particularly those in intensive care units or those with central venous catheters, the risk of developing invasive candidiasis increases substantially.^[2]

Causes: Why Does Candida Overgrow?

Under healthy conditions, your body maintains a careful balance between Candida yeast and beneficial bacteria. You can imagine this as a scale with bacteria on one side and yeast on the other, staying level and stable. When something tips this scale, Candida can multiply rapidly and cause an infection.^[1]

Several factors can disrupt this natural balance. Antibiotics are a common trigger because while they kill harmful bacteria causing your illness, they also eliminate beneficial bacteria that normally keep Candida under control. This creates an opportunity for yeast to flourish unchecked.^[4]

Hormonal changes play a significant role, particularly in vaginal yeast infections. Pregnancy, menopause, and even regular menstrual cycles can alter the vaginal environment in ways that favor yeast growth. Women taking birth control pills or hormone therapy may also experience changes that increase their susceptibility to these infections.^[1]

Medical conditions that weaken the immune system create favorable conditions for Candida overgrowth. People with HIV/AIDS, cancer, or diabetes face higher risks. In diabetes specifically, high blood sugar levels act as food for yeast, helping it grow more vigorously. Individuals taking medications that suppress the immune system, such as corticosteroids or chemotherapy drugs, are also more vulnerable.^[1]

Stress, both physical and emotional, can affect your body’s defenses and create opportunities for yeast infections. An unhealthy diet high in refined carbohydrates, sugar, or yeast may contribute to creating an environment where Candida thrives, though the direct connection is still being studied.^[1]

Risk Factors: Who Gets Candida Infections?

While anyone can develop a Candida infection, certain groups and circumstances increase the likelihood. Understanding these risk factors can help you recognize when you might be more vulnerable to these infections.

People with weakened immune systems stand at the forefront of risk. This includes individuals receiving chemotherapy, those who have undergone organ transplants, people with HIV/AIDS, and anyone taking immunosuppressive medications. Their bodies simply lack the robust defenses needed to keep Candida populations in check.^[2]

Healthcare settings present particular risks. Hospitalized patients, especially those in intensive care units, face elevated chances of developing serious Candida infections. The presence of medical devices like central venous catheters, which provide a pathway from outside the body to internal tissues, can inadvertently carry yeast from the skin’s surface into the bloodstream. People on dialysis or those requiring tube feeding also face increased risks.^[2]

For vaginal yeast infections, specific factors come into play. Women who are pregnant experience hormonal shifts that make yeast infections more likely. Those taking antibiotics or corticosteroids disrupt the normal bacterial balance in the vagina. Having uncontrolled diabetes creates an environment rich in sugar that yeast finds favorable. Even behaviors like wearing tight, non-breathable clothing or staying in wet swimsuits can create warm, moist conditions that encourage yeast growth.^[9]

Infants born prematurely have underdeveloped immune systems that make them more susceptible to Candida infections. Babies in diapers commonly develop yeast-related diaper rash because the diaper area stays warm and moist—perfect conditions for yeast multiplication.^[4]

People who wear dentures, have poor oral hygiene, or use inhaled corticosteroids for conditions like asthma face higher risks of developing oral thrush. Those who inject drugs also have increased susceptibility to oral Candida infections.^[9]

Symptoms: What Does a Candida Infection Feel Like?

The symptoms of Candida infection vary considerably depending on where the infection occurs in your body. Recognizing these signs helps you know when to seek medical attention.

When Candida affects the mouth and throat, causing thrush, you’ll typically notice white or yellowish patches on your tongue, inner cheeks, gums, tonsils, or the roof of your mouth. These patches often look like cottage cheese and may bleed slightly if you try to scrape them off. The affected areas usually feel sore, and you might experience redness around the patches. Some people have difficulty swallowing or notice cracking and redness at the corners of their mouth. You might also lose your sense of taste temporarily.^[3]

Vaginal yeast infections create their own distinct set of symptoms. The most prominent is often intense itching and irritation in and around the vaginal opening. This itching can be severe enough to interfere with daily activities and sleep. You’ll likely experience burning sensations, particularly during urination or sexual intercourse. The vagina and surrounding tissues may appear red and swollen. Vaginal discharge changes, becoming thick, white, and clumpy—again, often compared to cottage cheese—though it typically doesn’t have a strong odor. The skin around the vaginal area may develop small cracks or tears from the inflammation.^[1]

Skin infections from Candida produce red, oozing patches that develop in moist skin folds. These areas might include under your breasts, in your armpits, around your buttocks, between your toes, or in the groin area. The affected skin typically feels itchy and may have a burning sensation. The patches often have a raised border with small bumps around the edges. In babies, this appears as diaper rash with bright red, bumpy skin in the diaper area.^[4]

When Candida affects the nails and surrounding skin, you’ll notice redness, swelling, and pain around the nail folds and cuticles. The affected area might feel tender to touch. In severe cases, the nail plate itself can separate from the nail bed underneath, and the nail may become discolored or thickened.^[1]

Some people with Candida infections report general symptoms like fatigue and tiredness, though these are less specific and often accompany other conditions. When Candida affects the esophagus, you might experience pain when swallowing and discomfort in your chest.^[1]

The most serious form, invasive candidiasis, presents with fever and chills that don’t respond to antibiotic treatment for bacterial infections. Because people who develop invasive candidiasis are usually already sick with other conditions, it can be difficult to distinguish which symptoms come from the Candida infection versus the underlying illness.^[1]

Prevention: Keeping Candida Under Control

While you can’t completely eliminate Candida from your body—nor would you want to, as it’s part of your natural ecosystem—you can take steps to prevent it from overgrowing and causing infections.

Good hygiene forms the foundation of prevention. Keep your skin clean and dry, paying special attention to areas where skin folds create warm, moist environments. After bathing or swimming, dry yourself thoroughly, particularly in skin folds. Change out of wet swimsuits or sweaty workout clothes promptly rather than staying in them for extended periods.^[1]

For preventing vaginal yeast infections, clothing choices matter. Wear cotton underwear, which allows your skin to breathe and doesn’t trap moisture like synthetic fabrics can. Avoid tight-fitting pants or pantyhose that create warm, moist conditions in the genital area. Some women find that sleeping without underwear helps keep the area dry and reduces infection risk.^[19]

After using the bathroom, always wipe from front to back. This simple habit prevents spreading yeast or bacteria from the anal area to the vagina or urinary tract. Avoid using douches, vaginal sprays, scented tampons, or perfumed powders in the genital area, as these products can disrupt the natural balance of bacteria and yeast.^[1]

Maintaining good oral hygiene helps prevent oral thrush. Brush your teeth regularly and thoroughly. If you use inhaled corticosteroids for asthma or other conditions, rinse your mouth or brush your teeth after each use. Denture wearers should clean their dentures properly and ensure they fit well.^[19]

Use antibiotics and corticosteroids only when prescribed by your healthcare provider, and take them exactly as directed. These medications are sometimes necessary to treat serious conditions, but they can increase your risk of yeast infections by disrupting your body’s natural bacterial balance. Tell your doctor if you frequently get yeast infections when taking antibiotics—they might be able to adjust your treatment plan.^[19]

If you have diabetes, keeping your blood sugar levels well-controlled is crucial. High blood sugar creates an environment that encourages yeast growth. Work with your healthcare team to maintain stable glucose levels through medication, diet, and lifestyle changes.^[9]

Some evidence suggests that eating yogurt with live bacterial cultures or taking probiotic supplements containing lactobacillus or acidophilus may help prevent some types of yeast infections by maintaining healthy bacterial populations in your body. However, more research is needed to fully understand how effective this approach is.^[9]

In healthcare settings, preventing serious invasive Candida infections involves different strategies. Healthcare providers may prescribe antifungal medications preventively for high-risk patients, such as those undergoing organ transplants, chemotherapy patients with very low white blood cell counts, or premature infants in nurseries with high rates of infection. Proper care of central venous catheters and following infection control practices also help prevent these serious infections.^[19]

Pathophysiology: How Candida Causes Disease

Understanding how Candida transforms from a harmless resident of your body to a disease-causing organism helps explain why infections occur and how treatments work.

In its normal state, Candida exists as a yeast—a single-celled organism that lives peacefully alongside billions of bacteria and other microorganisms that make up your body’s natural microbiome. This community of organisms maintains a careful balance. Beneficial bacteria compete with Candida for space and nutrients, produce substances that inhibit yeast growth, and help maintain an environment that doesn’t favor yeast multiplication.^[6]

When something disrupts this balance—such as antibiotics killing beneficial bacteria, hormonal changes altering the local environment, or immune system weakness reducing the body’s defenses—Candida seizes the opportunity to multiply. The yeast begins reproducing rapidly, growing in numbers that overwhelm the body’s ability to keep it in check.^[1]

As Candida overgrows, it can change form. In favorable conditions, it develops thread-like structures called hyphae or pseudohyphae. These filaments allow the yeast to penetrate deeper into tissues, much like roots growing into soil. This penetration triggers inflammation as your immune system recognizes the invasion and responds by sending white blood cells to the area. This immune response causes many of the symptoms you experience—the redness, swelling, pain, and discharge associated with Candida infections.^[3]

In mucous membranes like those in your mouth or vagina, the overgrown Candida forms a layer of yeast cells, hyphae, and inflammatory debris. In oral thrush, this creates the characteristic white patches. When wiped away, these patches reveal red, sometimes bleeding tissue underneath where the inflammation is most active.^[3]

On skin, particularly in warm, moist folds, Candida thrives because these conditions provide the perfect environment for yeast growth. The infection causes the outer layer of skin to break down, creating the red, oozing appearance typical of cutaneous candidiasis. The surrounding skin often becomes macerated—soft and broken down from prolonged moisture exposure.^[4]

In vaginal yeast infections, changes in the vaginal pH (its acidity level) and alterations in hormone levels create conditions that favor yeast over protective bacteria. The normal acidic environment that helps control yeast populations becomes less effective. Glycogen in vaginal tissues, which increases during certain hormonal states like pregnancy, provides food for yeast to multiply.^[9]

When Candida enters the bloodstream in invasive candidiasis, the yeast can travel throughout the body and establish infections in multiple organs. The heart valves, kidneys, liver, spleen, brain, and eyes are particularly vulnerable. Once inside these organs, Candida triggers severe inflammatory responses that can damage normal tissue function. In the bloodstream itself, the infection can trigger widespread inflammation that affects blood pressure and organ function, leading to sepsis—a life-threatening condition where the body’s response to infection causes damage to its own tissues.^[25]

The body’s immune response determines much of the infection’s severity. People with healthy immune systems usually contain Candida infections to surface areas like skin and mucous membranes. Those with weakened immunity cannot mount an adequate response, allowing the yeast to penetrate deeper and spread more widely, leading to more severe and potentially life-threatening infections.^[3]