Yes, Candida is a fungus. It belongs to the kingdom Fungi, specifically within a group called Ascomycota, the same broad category that includes common yeasts used in baking and brewing. Candida naturally lives on and inside the human body in small amounts, primarily on the skin, in the mouth, and throughout the intestines. It only becomes a problem when something disrupts the body’s ability to keep it in check.
What Type of Fungus Candida Is
Fungi come in many forms, from mushrooms to molds to microscopic yeasts. Candida falls into the yeast category, meaning it’s a single-celled organism invisible to the naked eye. But it has an unusual trick: it can shift between different physical forms. In its typical state, Candida grows as round yeast cells. Under certain conditions, it can sprout elongated filaments called hyphae, which help it penetrate into tissues and cause infection. This shape-shifting ability is one of the key reasons Candida is so effective as a pathogen.
The species most people are referring to when they say “Candida” is Candida albicans, which causes roughly 65% of all Candida infections. But there are several other species that matter clinically. About 90% of infections trace back to just five species: C. albicans, C. glabrata (11.3% of infections), C. tropicalis (7.2%), C. parapsilosis (6%), and C. krusei (2.4%).
Where Candida Lives in Your Body
Candida is a normal part of the human microbiome. It lives in small amounts on your skin, inside your mouth, in your gut, and in the vaginal tract. The main reservoir is the gastrointestinal tract, where it coexists with trillions of bacteria that help keep its population in check. It’s also present on tooth surfaces. In healthy people, Candida causes no symptoms at all. Your immune system and the competing bacteria in your microbiome form a two-layer defense that prevents Candida from growing out of control.
How Candida Goes From Harmless to Harmful
The shift from quiet colonizer to active infection happens when one or both of those defenses break down. Antibiotics are one of the most common triggers because they kill off the bacteria that normally compete with Candida for space and nutrients. With that competition removed, Candida populations can bloom. Steroids, chemotherapy, and other immunosuppressive medications also open the door by weakening the immune system’s ability to patrol fungal growth.
Certain health conditions raise your risk significantly. Diabetes creates an environment with higher sugar levels in tissues and mucous membranes, which Candida thrives on. HIV/AIDS and cancer both compromise immune function. Pregnancy and hormonal contraceptives change the vaginal environment in ways that favor Candida overgrowth. Even something as simple as wearing dentures, having a dry mouth, or smoking can increase the risk of oral Candida infections.
At the cellular level, Candida takes advantage of these openings by secreting enzymes that damage tissue and switching into its filamentous hyphal form, which can physically push into deeper layers of skin and mucous membranes.
Types of Candida Infections
Most Candida infections are superficial, meaning they affect the skin or mucous membranes. Oral thrush produces white patches on the tongue and inner cheeks. Vaginal yeast infections cause itching, discharge, and irritation. Skin infections tend to appear in warm, moist folds of the body. These are uncomfortable but rarely dangerous, and they respond well to antifungal treatment.
Invasive candidiasis is a different story entirely. This occurs when Candida enters the bloodstream (a condition called candidemia) and spreads to internal organs. It primarily affects people who are already critically ill: those in intensive care units, patients with central venous catheters, people receiving nutrition through an IV, organ transplant recipients, and individuals on long courses of broad-spectrum antibiotics. Premature infants and people on hemodialysis also face elevated risk. CDC surveillance data from 2017 to 2021 found that the all-cause in-hospital mortality rate for candidemia was 32.6%, and that figure climbed from about 27% in 2017 to 36% in 2021.
Candida Auris: A Growing Concern
One species deserves special attention. Candida auris is classified as an urgent public health threat because of its extensive resistance to antifungal drugs. A growing number of C. auris cases show resistance to all three major classes of antifungals, which can make infections extremely difficult to treat. Bloodstream infections with C. auris carry a crude mortality rate between 30% and 70%.
What makes C. auris especially dangerous in hospital settings is its ability to survive outside the human body for extended periods. It can persist on surfaces like bed rails, medical devices, and the hands of healthcare workers. Unlike most Candida species, which primarily colonize the gut, C. auris prefers the skin, making person-to-person transmission more likely. It also tolerates heat up to 42°C and high-salt environments, which helps it resist standard cleaning measures. To make matters worse, standard laboratory methods frequently misidentify C. auris as other Candida species, delaying appropriate treatment.
How Candida Infections Are Treated
Because Candida is a fungus, it requires antifungal medications rather than antibiotics. Antibiotics target bacteria and have no effect on fungal cells. There are several classes of antifungal drugs, each working differently. Some target a component of the fungal cell membrane called ergosterol, either blocking its production or binding directly to it and punching holes in the membrane. Others attack the fungal cell wall, disrupting its structural integrity.
For superficial infections like oral thrush or vaginal yeast infections, treatment is typically straightforward. Topical or oral antifungals resolve most cases within days to a couple of weeks. Invasive candidiasis requires more aggressive treatment, usually with intravenous antifungals administered in a hospital setting, and recovery depends heavily on the patient’s underlying health. The rise of drug-resistant species like C. auris is making treatment selection more complex, as clinicians increasingly need to test which drugs a particular strain still responds to before choosing a course of action.