Signs and symptoms of candidiasis vary depending on the area affected. Most candidal infections result in minimal complications such as redness, itching, and discomfort, though complications may be severe or even fatal if left untreated in certain populations. In healthy (immunocompetent) persons, candidiasis is usually a localized infection of the skin, fingernails or toenails (onychomycosis), or mucosal membranes, including the oral cavity and pharynx (thrush), esophagus, and the genitalia (vagina, penis, etc.); less commonly in healthy individuals, the gastrointestinal tract, urinary tract, and respiratory tract are sites of candida infection.

In immunocompromised individuals, "Candida" infections in the esophagus occur more frequently than in healthy individuals and have a higher potential of becoming systemic, causing a much more serious condition, a fungemia called candidemia. Symptoms of esophageal candidiasis include difficulty swallowing, painful swallowing, abdominal pain, nausea, and vomiting.

Thrush is commonly seen in infants. It is not considered abnormal in infants unless it lasts longer than a few weeks.

Infection of the vagina or vulva may cause severe itching, burning, soreness, irritation, and a whitish or whitish-gray cottage cheese-like discharge. Symptoms of infection of the male genitalia (balanitis thrush) include red skin around the head of the penis, swelling, irritation, itchiness and soreness of the head of the penis, thick, lumpy discharge under the foreskin, unpleasant odour, difficulty retracting the foreskin (phimosis), and pain when passing urine or during sex.

Common symptoms of gastrointestinal candidiasis in healthy individuals are anal itching, belching, bloating, indigestion, nausea, diarrhea, gas, intestinal cramps, vomiting, and gastric ulcers. Perianal candidiasis can cause anal itching; the lesion can be erythematous, papular, or ulcerative in appearance, and it is not considered to be a sexually transmissible disease. Abnormal proliferation of the candida in the gut may lead to dysbiosis. While it is not yet clear, this alteration may be the source of symptoms generally described as the irritable bowel syndrome, and other gastrointestinal diseases.

Three main clinical appearances of candidiasis are generally recognized: pseudomembranous, erythematous (atrophic) and hyperplastic. Most often, affected individuals display one clear type or another, but sometimes there can be more than one clinical variant in the same person.

Patients with esophageal candidiasis present with odynophagia, or painful swallowing. Longstanding esophageal candidiasis can result in weight loss. There is often concomittant thrush.

Some patients present with esophageal candidiasis as a first presentation of systemic candidiasis.

Acute pseudomembranous candidiasis is a classic form of oral candidiasis, commonly referred to as thrush. Overall, this is the most common type of oral candidiasis, accounting for about 35% of oral candidiasis cases.

It is characterized by a coating or individual patches of pseudomembranous white slough that can be easily wiped away to reveal erythematous (reddened), and sometimes minimally bleeding, mucosa beneath. These areas of pseudomembrane are sometimes described as "curdled milk", or "cottage cheese". The white material is made up of debris, fibrin, and desquamated epithelium that has been invaded by yeast cells and hyphae that invade to the depth of the stratum spinosum. Due to the fact that an erythematous surface is revealed beneath the pseudomembranes, some consider pseudomembranous candidiasis and erythematous candidiasis stages of the same entity. Some sources state that if there is bleeding when the pseudomembrane is removed, then the mucosa has likely been affected by an underlying process such as lichen planus or chemotherapy. Pseudomembraneous candidiasis can involve any part of the mouth, but usually it appears on the tongue, buccal mucosae or palate.

It is classically an acute condition, appearing in infants, people taking antibiotics or immunosuppressant medications, or immunocompromising diseases. However, sometimes it can be chronic and intermittent, even lasting for many years. Chronicity of this subtype generally occurs in immunocompromised states, (e.g., leukemia, HIV) or in persons who use corticosteroids topically or by aerosol. Acute and chronic pseudomembranous candidiasis are indistinguishable in appearance.

Candidiasis may be divided into these types:

- Mucosal candidiasis

- Oral candidiasis (thrush, oropharyngeal candidiasis)

- Pseudomembranous candidiasis

- Erythematous candidiasis

- Hyperplastic candidiasis

- Denture-related stomatitis — "Candida" organisms are involved in about 90% of cases

- Angular cheilitis — "Candida" species are responsible for about 20% of cases, mixed infection of "C. albicans" and "Staphylococcus aureus" for about 60% of cases.

- Median rhomboid glossitis

- Candidal vulvovaginitis (vaginal yeast infection)

- Candidal balanitis — infection of the glans penis, almost exclusively occurring in uncircumcised males

- Esophageal candidiasis (candidal esophagitis)

- Gastrointestinal candidiasis

- Respiratory candidiasis

- Cutaneous candidiasis

- Candidial folliculitis

- Candidal intertrigo

- Candidal paronychia

- Perianal candidiasis, may present as pruritus ani

- Candidid

- Chronic mucocutaneous candidiasis

- Congenital cutaneous candidiasis

- Diaper candidiasis: an infection of a child's diaper area

- Erosio interdigitalis blastomycetica

- Candidial onychomycosis (nail infection) caused by "Candida"

- Systemic candidiasis

- Candidemia, a form of fungemia which may lead to sepsis

- Invasive candidiasis (disseminated candidiasis) — organ infection by "Candida"

- Chronic systemic candidiasis (hepatosplenic candidiasis) — sometimes arises during recovery from neutropenia

- Antibiotic candidiasis (iatrogenic candidiasis)

Symptoms of invasive candidiasis can be confused with other medical conditions, however, the most common symptoms are fever and chills that do not improve with antibiotic treatment. Other symptoms develop as the infection spreads, depending on which parts of the body are involved.

Invasive candidiasis can manifest as serious diseases including as fungemia, endocarditis, endophthalmitis, osteomyelitis, and central nervous system infections.

Esophageal candidiasis is an opportunistic infection of the esophagus by "Candida albicans". The disease usually occurs in patients in immunocompromised states, including post-chemotherapy and in AIDS. However, it can also occur in patients with no predisposing risk factors, and is more likely to be asymptomatic in those patients. It is also known as candidal esophagitis or monilial esophagitis.

Systemic candidiasis is an infection of Candida albicans causing disseminated disease and sepsis, invariably when host defenses are compromised.

Symptoms can range from mild to extreme—often described as extreme flu-like symptoms. Many symptoms may be associated with fungemia, including pain, acute confusion, chronic fatigue, and infections. Skin infections can include persistent or non-healing wounds and lesions, sweating, itching, and unusual discharge or drainage.

Despite the alternative name for this condition, "denture sore mouth", it is usually painless and asymptomatic. The appearance of the involved mucosa is erythematous (red) and edematous (swollen), sometimes

with petechial hemorrhage (pin-points of bleeding). This usually occurs beneath an upper denture. Sometimes angular cheilitis can coexist, which is inflammation of the corners of the mouth, also often associated with "Candida albicans". Stomatitis rarely develops under a lower denture. The affected mucosa is often sharply defined, in the shape of the covering denture.

The Newton classification divides denture-related stomatitis into three types based on severity. Type one may represent an early stage of the condition, whilst type two is the most common and type three is uncommon.

- Type 1 - Localized inflammation or pinpoint hyperemia

- Type 2 - More diffuse erythema (redness) involving part or all of the mucosa which is covered by the denture

- Type 3 - Inflammatory nodular/papillary hyperplasia usually on the central hard palate and the alveolar ridge

The symptoms of this condition are as follows:hyperkeratosis, skin ulcer, dyspareunia, endocardium abnormality, vision problems, hepatitis, seizures, hematuria and meningitis

Fungemia or fungaemia is the presence of fungi or yeasts in the blood. The most common type, also known as candidemia, candedemia, or systemic candidiasis, is caused by "Candida" species, but infections by other fungi, including "Saccharomyces", "Aspergillus" and "Cryptococcus", are also called fungemia. It is most commonly seen in immunosuppressed or immunocompromised patients with severe neutropenia, cancer patients, or in patients with intravenous catheters. It has been suggested the otherwise immunocompetent patients taking infliximab may be at a higher risk for fungemia.

Diagnosis is difficult, as routine blood cultures have poor sensitivity.

There are no symptoms associated with the lesion itself, although many and varied symptoms and signs may be associated with the underlying cause of immunosuppression. The lesion is a white patch, which almost exclusively occurs on the lateral surfaces of the tongue, although rarely it may occur on the buccal mucosa, soft palate, pharynx or esophagus. The lesion may grow to involve the dorsal surface of the tongue. The texture is vertically corrugated ("hairy") or thickly furrowed and shaggy in appearance.

Chronic mucocutaneous candidiasis is an immune disorder of T cells, it is characterized by chronic infections with "Candida" that are limited to mucosal surfaces, skin, and nails. It can also be associated with other types of infections, such as human papilloma virus. An association with chromosome 2 has been identified.

Hairy leukoplakia (also known as oral hairy leukoplakia, OHL, or HIV-associated hairy leukoplakia), is a white patch on the side of the tongue with a corrugated or hairy appearance. It is caused by Epstein-Barr virus (EBV) and occurs usually in persons who are immunocompromised, especially those with human immunodeficiency virus infection/acquired immunodeficiency syndrome (HIV/AIDS). This white lesion cannot be scraped off. The lesion itself is benign and does not require any treatment, although its appearance may have diagnostic and prognostic implications for the underlying condition.

Depending upon what definition of leukoplakia is used, hairy leukoplakia is sometimes considered a subtype of leukoplakia, or a distinct diagnosis.

Rarely is any soreness associated with the condition. Apart from the appearance of the lesion, there are usually no other signs or symptoms. The typical appearance of the lesion is an oval or rhomboid shaped area located in the midline of the dorsal surface of the tongue, just anterior (in front) of the sulcus terminalis. The lesion is usually symmetric, well demarcated, erythematous and depapillated, which has a smooth, shiny surface. Less typically, the lesion may be hyperplastic or lobulated and exophytic. There may be candidal lesions at other sites in the mouth, which may lead to a diagnosis of chronic multifocal oral candidiasis. Sometimes an approximating erythematous lesion is present on the palate as the tongue touches the palate frequently. The lesion is typically 2–3 cm in its longest dimension.

Predisposing factors include smoking, denture wearing, use of corticosteroid sprays or inhalers and human immunodeficiency virus (HIV) infection. "Candida" species even in healthy people mainly colonizes the posterior dorsal tongue. Median rhombiod glossitis is thought to be a type of chronic atrophic (or erythematous) candidiasis. Microbiological culture of the lesion usually shows "Candida" mixed with bacteria.

Enterocolitis or coloenteritis is an inflammation of the digestive tract, involving enteritis of the small intestine and colitis of the colon. It may be caused by various infections, with bacteria, viruses, fungi, parasites, or other causes. Common clinical manifestations of enterocolitis are frequent diarrheal defecations, with or without nausea, vomiting, abdominal pain, fever, chills, alteration of general condition. General manifestations are given by the dissemination of the infectious agent or its toxins throughout the body, or – most frequently – by significant losses of water and minerals, the consequence of diarrhea and vomiting.

Among the causal agents of acute enterocolitis are:

- bacteria: "Salmonella", "Shigella", "Escherichia coli", "Campylobacter" etc.;

- viruses: enteroviruses, rotaviruses, Norwalk virus, adenoviruses;

- fungi: candidiasis, especially in immunosuppressed patients or who have previously received prolonged antibiotic treatment;

- parasites: "Giardia lamblia" (with high frequency of infestation in the population, but not always with clinical manifestations), "Balantidium coli", "Blastocystis homnis", "Cryptosporidium" (diarrhea in people with immunosuppression), "Entamoeba histolytica" (produces the amebian dysentery, common in tropical areas).

A woman may have vaginal itching or burning and may notice a discharge.

The discharge may be excessive in amounts or abnormal in color(such as yellow, gray, or green).

The following symptoms may indicate the presence of infection:

- Irritation or itching of the genital area

- inflammation (irritation, redness, and swelling caused by the presence of extra immune cells) of the labia majora, labia minora, or perineal area

- vaginal discharge

- foul vaginal odor

- pain/irritation with sexual intercourse

Vaginitis is inflammation of the vagina. In most cases, it is a symptom of an infection of the vagina. Vulvovaginitis, is an inflammation of the vagina and vulva. Infection can result in discharge, itching and pain.

The three main causes of vaginitis are infections by bacteria (bacterial vaginosis), yeast (vaginal candidiasis), or the protozoan that causes trichomoniasis. A woman may have multiple infections at any one time. If there is discomfort in the vulvovaginal area, women can request their health care providers evaluate for the presence of an infection.

Bumblefoot (ulcerative pododermatitis) is a bacterial infection and inflammatory reaction on the feet of birds, rodents, and rabbits. Ulcerative pododermatitis is referred to as "sore hocks" when it affects a rabbit and "bumblefoot" when it affects a bird. The terms "sore hocks" and "bumblefoot" are used interchangeably when describing ulcerative pododermatitis in rodents. The infection can usually be attributed to poor husbandry practices, therefore is much more likely to occur in captive animals than in those in the wild. It is caused by bacteria, namely strains of "Staphylococcus", "Pseudomonas" and "Escherichia coli" "(E. coli)", with "S. aureus" being the most common cause of the infection.

Leukoplakia of the esophagus is rare compared to oral leukoplakia. The relationship with esophageal cancer is unclear because the incidence of esophageal leukoplakia is so low. It usually appears as a small, nearly opaque white lesion that may resemble early esophageal squamous cell carcinoma. The histologic appearance is similar to oral leukoplakia, with hyperkeratosis and possible dysplasia.

Specific types of enterocolitis include:

- necrotizing enterocolitis (most common in premature infants)

- pseudomembranous enterocolitis (also called "Pseudomembranous colitis")