Yeast Infection
Yeast infection (also known as candidiasis ) is a vaginal infection caused by the fungal organism Candida albicans.
Yeast are tiny organisms that normally live in small numbers on the skin and inside the vagina. The acidic environment of the vagina helps to keep yeast from growing. If the vagina becomes less acidic, too many yeast can grow and cause a vaginal infection.
Vaginal yeast infections are very common. About 75% of women have a yeast infection during their lives. And almost half of women have two or more yeast infections.
Vaginal yeast infections are not considered to be a sexually transmitted infection. However, 12% to 15% of men will develop symptoms such as itching and penile rash following sexual contact with an infected partner. Yeast infection can occur in women who have never been sexually active but are more common in women who are sexually active. Yeast infections are no more frequent in women who have sex frequently, but may develop more frequently in women who receive oral sex.
The symptoms of a vaginal yeast infection include:
- Vaginal itching, burning and irritation - most obvious symptoms
- Thick, white discharge resembling cottage cheese; however, some women may experience little or no vaginal discharge
- Discomfort around the vaginal opening, especially if urine touches the area
- Pain or discomfort during sexual intercourse
These symptoms get worse the longer you go without treatment.
Yeast infections are caused by an overgrowth of the Candida albicans fungus. This happens when the environment has certain favorable conditions that allow growth and nourishment of Candida albicans. An environment that makes it difficult for the other microorganisms to survive may also cause an imbalance and lead to a yeast infection.
Yeast overgrowth usually occurs as the result of:
- High stress. Doctors don't fully understand the connection between stress and yeast, but many women report an increase in yeast infections during times of high stress. It is possible that part of the explanation lies in the effects chronic or uncontrolled stress have on the body's immune function.
- Hormonal fluctuations during the menstrual cycle. Some women get mild yeast infections towards the end of their menstrual periods, possibly in response to the body's hormonal changes. These mild infections sometimes go away without treatment as the menstrual cycle progresses.
- Pregnancy. The hormonal changes associated with pregnancy alter the vaginal acidity and increase the production of blood sugar, which provides food for yeast.
- Poorly ventilated clothing and underwear. Poor ventilation in the genital area may exacerbate or perpetuate (but not cause) yeast infections. Cothing (especially underwear) that is too tight or made of materials like nylon that trap heat and moisture might lead to yeast infections because yeast can thrive in this type of environment.
- Diabetes and elevated blood sugar levels. Since yeasts feed on sugar, conditions that raise vaginal glucose levels could promote their growth. When diabetes is poorly controlled or uncontrolled, the level of sugar in the urine and vagina, as well as in the blood, increases, providing food that can fuel increased yeast growth. Indeed, repeated yeast infections in the vagina or mouth are often the clue that prompts doctors to test patients for the presence of previously undiagnosed diabetes.
- Antibiotics. Candida live in the healthy vagina in balance with other microorganisms, especially lactobacilli. The antibiotics change the normal balance between organisms in the vagina by suppressing the growth of protective bacteria that normally have an antifungal effect. Some antibiotics, especially tetracycline, also appear to stimulate the growth of yeast organisms.
- Birth control pill or hormonal contraception. Infection is common among women who use estrogen-containing birth control pills. This is due to the increased level of estrogen in the body. The increased hormone level causes changes in the vaginal environment that make it perfect for fungal growth and nourishment.
- Irritation. Moisture and irritation of the vagina also seem to encourage yeast to grow. Some women may react to certain dyes or perfumes in soaps, bath gels or lotions, sanitary products, and laundry detergents. When the reaction causes irritation, that can set the stage for a yeast infection.
Proper treatment cures up to 90% of vaginal yeast infections within two weeks or less, often within a few days. A small number of people will have repeat infections. Usually, these will improve with repeated treatment.
Vaginal yeast infections can be treated with antifungal medicines that are inserted directly into the vagina as tablets, creams, ointments or suppositories. These medications include butoconazole (Femstat), clotrimazole (Clotrimaderm, Canesten), miconazole (Monistat, Monazole, Micozole), nystatin (several brand names), tioconazole (GyneCure) and terconazole (Terazole).
A single dose of oral fluconazole (Diflucan Oral) also may be used, although this treatment is not recommended during pregnancy.
Most doctors prefer to treat vaginal yeast infections with vaginal tablets or suppositories rather than oral medications.
Treatment of sex partners is not usually necessary, since most vaginal yeast infections are not transmitted sexually. However, if a male sex partner shows symptoms of yeast infection (redness, irritation and/or itching at the tip of the penis), he may need to be treated with an antifungal cream or ointment.
References and Sources:
- 1. Vaginal Yeast Infections The Federal Source for Women's Health Information
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