The exact cause of VIN is unknown. Studies are being done to determine the cause of VIN. The following factors have been associated with VIN:

- HPV (Human Papilloma Virus)

- HSV-2 (Herpes simplex Virus - Type 2)

- Smoking

- Immunosuppression

- Chronic vulvar irritation

- Conditions such as Lichen Sclerosus

All sores involve a breakdown in the walls of the fine membrane of the vaginal wall. The most common of these are abrasions and small ulcers caused by trauma. While these can be inflicted during rape most are actually caused by excessive rubbing from clothing or improper insertion of a sanitary tampon. The typical ulcer or sore caused by syphilis is painless with raised edges. These are often undetected because they occur mostly inside the vagina. The sores of herpes which occur with vesicles are extremely tender and may cause such swelling that passing urine is difficult. In the developing world, a group of parasitic diseases also cause vaginal ulceration, such as leishmaniasis, but these are rarely encountered in the west. All of the aforementioned local vulvovaginal diseases are easily treated. Often, only shame prevents patients from presenting for treatment.

Vaginitis an inflammation of the vagina, such as caused by infection, hormone disturbance and irritation/allergy.

Vulvitis, inflammation of the vulva, can have a variety of etiologies in children and adolescents, including allergic dermatitis, contact dermatitis, lichen sclerosus, and infections with bacteria, fungi, and parasites. Dermatitis in infants is commonly caused by a soiled diaper being left on for an extended period of time. Increasing the frequency of diaper changes and topical application of emollients are sufficient to resolve most cases. Dermatitis of the vulva in older children is usually caused by exposure to an irritant (e.g. scented products that come into contact with the vulva, laundry detergent, soaps, etc.) and is treated with preventing exposure and encouraging sitz baths with baking soda as the vulvar skin heals. Other treatment options for vulvar dermatitis include oral hydroxyzine hydrochloride or topical hydrocortisone.

Lichen sclerosus is another common cause of vulvitis in children, and it often affects an hourglass or figure eight-shaped area of skin around the anus and vulva. Symptoms of a mild case include skin fissures, loss of skin pigment (hypopigmentation), skin atrophy, a parchment-like texture to the skin, dysuria, itching, discomfort, and excoriation. In more severe cases, the vulva may become discolored, developing dark purple bruising (ecchymosis), bleeding, scarring, attenuation of the labia minora, and fissures and bleeding affecting the posterior fourchette. Its cause is unknown, but likely genetic or autoimmune, and it is unconnected to malignancy in children. If the skin changes are not obvious on visual inspection, a biopsy of the skin may be performed to acquire an exact diagnosis. Treatment for vulvar lichen sclerosus may consist of topical hydrocortisone in mild cases, or stronger topical steroids (e.g. clobetasol propionate). Preliminary studies show that 75% of cases do not resolve with puberty.

Organisms responsible for vulvitis in children include pinworms ("Enterobius vermicularis"), "Candida" yeast, and group A hemolytic "Streptococcus". Though pinworms mainly affect the perianal area, they can cause itching and irritation to the vulva as well. Pinworms are treated with albendazole. Vulvar "Candida" infections are uncommon in children, and generally occur in infants after antibiotic therapy, and in children with diabetes or immunodeficiency. "Candida" infections cause a red raised vulvar rash with satellite lesions and clear borders, and are diagnosed by microscopically examining a sample treated with potassium hydroxide for hyphae. They are treated with topical butoconazole, clotrimazole, or miconazole. "Streptococcus" infections are characterized by a dark red discoloration of the vulva and introitus, and cause pain, itching, bleeding, and dysuria. They are treated with antibiotics.

Vaccinating girls with HPV vaccine before their initial sexual contact has been claimed to reduce incidence of VIN.

Vulvitis is inflammation of the vulva, the external female mammalian genitalia that include the labia majora, labia minora, clitoris, and introitus (the entrance to the vagina). It may co-occur with vaginitis, inflammation of the vagina, and may have infectious or non-infectious causes.

The thickness of the mucosa may be an important factor in aphthous stomatitis. Usually, ulcers form on the thinner, non-keratinizing mucosal surfaces in the mouth. Factors which decrease the thickness of mucosa increase the frequency of occurrence, and factors which increase the thickness of the mucosa correlate with decreased ulceration.

The nutritional deficiencies associated with aphthous stomatitis (B12, folate, and iron) can all cause a decrease in the thickness of the oral mucosa (atrophy).

Local trauma is also associated with aphthous stomatitis, and it is known that trauma can decrease the mucosal barrier. Trauma could occur during injections of local anesthetic in the mouth, or otherwise during dental treatments, frictional trauma from a sharp surface in the mouth such as broken tooth, or from tooth brushing.

Hormonal factors are capable of altering the mucosal barrier. In one study, a small group of females with apthous stomatitis had fewer occurrences of aphthous ulcers during the luteal phase of the menstrual cycle or with use of the contraceptive pill. This phase is associated with a fall in progestogen levels, mucosal proliferation and keratinization. This subgroup often experiences remission during pregnancy. However, other studies report no correlation between aphthous stomatitis and menstrual period, pregnancy or menopause.

Aphthous stomatitis is common in people who smoke, and there is also a correlation between habit duration and severity of the condition. Tobacco use is associated with an increase in keratinization of the oral mucosa. In extreme forms, this may manifest as leukoplakia or stomatitis nicotina (smoker's keratosis). This increased keratinization may mechanically reinforce the mucosa and reduce the tendency of ulcers to form after minor trauma, or present a more substantial barrier to microbes and antigens, but this is unclear. Nicotine is also known to stimulate production of adrenal steroids and reduce production of TNF-α, interleukin-1 and interleukin-6. Smokeless tobacco products also seem to protect against aphthous stomatitis. Cessation of smoking is known to sometimes precede the onset of aphthous stomatitis in people previously unaffected, or exacerbate the condition in those who were already experiencing aphthous ulceration. Despite this correlation, starting smoking again does not usually lessen the condition.

Various antigenic triggers have been implicated as a trigger, including L forms of streptococci, herpes simplex virus, varicella-zoster virus, adenovirus, and cytomegalovirus. Some people with aphthous stomatitis may show herpes virus within the epithelium of the mucosa, but without any productive infection. In some persons, attacks of ulceration occur at the same time as asymptomatic viral shedding and elevated viral titres.

In some instances, recurrent mouth ulcers may be a manifestation of an allergic reaction. Possible allergens include certain foods ("e.g.", chocolate, coffee, strawberries, eggs, nuts, tomatoes, cheese, citrus fruits, benzoates, cinnamaldehyde, and highly acidic foods), toothpastes, and mouthwashes. Where dietary allergens are responsible, mouth ulcers usually develop within about 12–24 hours of exposure.

Sodium lauryl sulphate (SLS), a detergent present in some brands of toothpaste and other oral healthcare products, may produce oral ulceration in some individuals. It has been shown that aphthous stomatitis is more common in people using toothpastes containing SLS, and that some reduction in ulceration occurs when a SLS-free toothpaste is used. Some have argued that since SLS is almost ubiquitously used in oral hygiene products, there is unlikely to be a true predisposition for aphthous stomatitis caused by SLS.

Many infections can cause oral ulceration (see table). The most common are herpes simplex virus (herpes labialis, primary herpetic gingivostomatitis), varicella zoster (chicken pox, shingles), and coxsackie A virus (hand, foot and mouth disease). Human immunodeficiency virus (HIV) creates immunodeficiencies which allow opportunistic infections or neoplasms to proliferate. Bacterial processes leading to ulceration can be caused by "Mycobacterium tuberculosis" (tuberculosis) and "Treponema pallidum" (syphilis).

Opportunistic activity by combinations of otherwise normal bacterial flora, such as aerobic streptococci, "Neisseria", "Actinomyces", spirochetes, and "Bacteroides" species can prolong the ulcerative process. Fungal causes include "Coccidioides immitis" (valley fever), "Cryptococcus neoformans" (cryptococcosis), and "Blastomyces dermatitidis" ("North American Blastomycosis"). Entamoeba histolytica, a parasitic protozoan, is sometimes known to cause mouth ulcers through formation of cysts.

Oral ulceration is a common reason for people to seek medical or dental advice. A breach of the oral mucosa probably affects most people at various times during life. For a discussion of the epidemiology of aphthous stomatitis, see Aphthous stomatitis#Epidemiology.

Kraurosis vulvae is a cutaneous condition characterized by atrophy and shrinkage of the skin of the vagina and vulva often accompanied by a chronic inflammatory reaction in the deeper tissues.

This condition occurs in association with denture wearing, and so those affected tend to be middle aged or older adults. 66-75% are estimated to occur in women. Epulis fissuratum is the third most common reactive lesion that occurs in the mouth, after peripheral giant cell granuloma and pyogenic granuloma.

In contrast to cutaneous LP, which is self limited, lichen planus lesions in the mouth may persist for many years, and tend to be difficult to treat, with relapses being common. Atrophic/erosive lichen planus is associated with a small risk of cancerous transformation, and so people with OLP tend to be monitored closely over time to detect any potential change early. Sometimes OLP can become secondarily infected with Candida organisms.

The overall prevalence of lichen planus in the general population is about 0.1–4.0%. It generally occurs more commonly in females, in a ratio of 3:2, and most cases are diagnosed between the ages of 30 and 60, but it can occur at any age.

Oral lichen planus is relatively common, It is one of the most common mucosal diseases. The prevalence in the general population is about 1.27–2.0%, and it occurs more commonly in middle aged people. OLP in children is rare. About 50% of females with oral lichen planus were reported to have undiagnosed vulvar lichen planus.

If the causative factor persists, tissue will become more fibrous over time.

A genital ulcer is located on the genital area, usually caused by a sexually transmitted disease such as genital herpes, syphilis, chancroid, or "Chlamydia trachomatis". Some other signs of having genital ulcers include enlarged lymph nodes in the groin area, or vesicular lesions, which are small, elevated sores or blisters. The syndrome may be further classified into penile ulceration and vulval ulceration for males and females respectively.

Genital ulcers are not strictly a sign of an STD. They can occur in patients with Behcet's syndrome, lupus, and some forms of rheumatoid arthritis (all non-communicable diseases). Genital tuberculosis, often caused by direct genital contact with infected sputum, can also present as genital ulcer.

The following measures are advisable for keeping the vulva and vagina healthy:

- Avoiding washing with soap, since soap disturbs the natural pH balance of the vagina. Some pH-balanced soaps exist, but their effects remain unclear. Other measures are seldom necessary or advisable. Two notable examples: so-called "feminine hygiene sprays" are unnecessary, may be generally harmful, and have been known to cause severe allergic reactions. Vaginal douching is generally not necessary and has been implicated in helping to cause bacterial vaginosis (BV) and candidiasis ("yeast infections").

- After using the toilet, wipe from the front toward the back to avoid introducing bacteria from the anal area into the vulva. Use non-perfumed, undyed toilet paper.

- Drink plenty of water and urinate frequently and as soon as possible when you feel the need, to help flush bacteria out of the urinary tract and avoid urinary tract infections. For the same reason, try to urinate before and after sex.

- Change out of a wet swimsuit or other wet clothes as soon as possible.

- Avoid fragrances, colours, and "deodorants" in products that contact the vulva/vagina: sanitary napkins, tampons, and toilet paper. Some women who are sensitive to these substances should also avoid bubble baths and some fabric detergents and softeners.

- Use a menstrual cup instead of sanitary pads or tampons. Menstrual cups are a new form of menstrual product that has recently been rapidly gaining in popularity as a greener, more cost-effective and healthier alternative to tampons and sanitary pads.

- Avoid wearing leather trousers, tight jeans, panties made of nylon or other synthetic fabrics, or pantyhose without an all-cotton crotch (not cotton covered by nylon - cut out the nylon panel if necessary).

- Anything which has been in contact with the anal area (see anal sex) should be thoroughly washed with soap and water or a disinfectant before coming in contact with the vulva or vagina.

- Use condoms during heterosexual intercourse, practise safer sex, know your sex partners, ask sex partners to practise basic hygiene of their genitals. Use artificial lubrication during the intercourse if the amount naturally produced is not enough.

- Be careful with objects inserted inside the vagina. Improper insertion of objects into any body opening can cause damage: infection, cutting, piercing, trauma, blood loss, etc.

- Avoid letting any contaminants inside the vagina, including dirt but especially sand.

- See your gynecologist regularly.

- Be careful while removing hair in this area.

Women who are unable to walk are more likely to have infections. The problem can be prevented according to above-mentioned and following measures:

- Wash crotch and rectal areas (with a soap-substitute if desired) and large amount of warm running water, every morning and evening. The disabled person can sit on a shower chair with an open seat or on a toilet. Use a shower head or water container to wash more directly.

- Use towel to dry.

- DO NOT use talcum/body powder, if desired use corn starch powder (corn-flour) on the skin of the genital area to absorb perspiration.

- Avoid sitting on plastic or synthetic materials for extended lengths of time.

- Wear loose underpants and change if soilage or wetness occurs.

The primary contributing factor to labial fusion is low estrogen levels. A vulva with low estrogen exposure, such as that of a preadolescent, has delicate epithelial lining and is therefore vulnerable to irritation. Conditions causing irritation, such as infection, inflammation and trauma, cause the edges of the labia minora to fuse together. The fusion typically begins at the posterior frenulum of the labia minora and continues anteriorly.

Most labial adhesions resolve spontaneously before puberty as estrogen levels increase and the vaginal epithelium becomes cornified.

Extramammary Paget's disease is usually seen in isolation and is associated with an underlying invasive malignancy about 12% of the time. It is associated with an underlying adnexal malignancy about 24% of the time. Paget's disease of the breast is almost always associated with an underlying invasive malignancy, i.e. breast cancer (e.g. mammary ductal carcinoma).

Little is known about the cause of vestibulodynia. A number of causes may be involved, including sub-clinical human papillomavirus infection, chronic recurrent candidiasis, or chronic recurrent bacterial vaginosis. Muscular causes have been implicated as well, since chronic vulvar pain may be the result of chronic hypertonic perivaginal muscles, leading to vaginal tightening and subsequent pain. Some investigators have postulated the existence of neurological causes, such as vestibular neural hyperplasia. Finally, psychological factors may contribute to or exacerbate the problem, since the anticipation of pain often results in a conditioned spasmodic reflex along with sexual desire and arousal problems.

Bednar's aphthae is a type of oral ulceration (mouth ulcers) which occurs in infants. The lesions are located on the palate and are caused by trauma. No treatment is required since the lesions heal within a few days.

The condition was first described in 1850, by the Austrian physician Alois Bednar (1816-1888).

Labial fusion can lead to urinary tract infection, vulvar vestibulitis and inflammation caused by chronic urine exposure. In severe cases, labial adhesions can cause complete obstruction of the urethra, leading to anuria and urinary retention.

Some conditions such as lichen sclerosus, squamous dysplasia or chronic vulvar itching may precede cancer. In younger women affected with vulvar cancer, risk factors include low socioeconomic status, multiple sexual partners, cigarette use and cervical cancer. Patients that are infected with HIV tend to be more susceptible to vulvar cancer as well. Human papillomavirus (HPV) infection is associated with vulvar cancer.

A wide variety of possible causes and treatments for vulvodynia are currently being explored. Moreover, there are probably several causes of vulvodynia, and some may be individual to the patient.

Possible causes include Sjogren's syndrome, the symptoms of which include chronic vaginal dryness. Others include genetic predisposition to inflammation, allergy or other sensitivity (for example: oxalates in the urine), an autoimmune disorder similar to lupus erythematosus or to eczema or to lichen sclerosus, infection (e.g., yeast infections, bacterial vaginosis, HPV, HSV), injury, and neuropathy—including an increased number of nerve endings in the vaginal area. Some cases seem to be negative outcomes of genital surgery, such as a Labioplasty. Initiation of hormonal contraceptives that contain low- dose estrogen before the age of 16 could predispose women to vulvar vestibulitis syndrome. A significantly lower pain threshold, especially in the posterior vestibulum, has also been associated with the use of hormonal contraceptives in women without vulvar vestibulitis syndrome. Pelvic floor dysfunction may be the underlying cause of some women's pain.

The percentage of women affected is not entirely clear, but estimates range as high as 16%. Many other conditions that are not truly vulvodynia (diagnosis is made by ruling out other causes of vulvar pain) could be confused with it. Vulvar pain is a quite frequent complaint in women's health clinics. Vulvodynia is a new term in the medical literature.