Candidiasis is another term for a yeast infection, which is caused by yeasts of the genus Candida. Candida yeasts can cause a multitude of different infections, and often colonize in the mucosa, causing vaginal, oral, or gastrointestinal infections. These are usually easily treated with anti-fungal medications. However, in those with severely weakened immune systems, candida can cause a serious blood infection called fungemia.
Candida yeasts are part of the natural flora of the human body, and live in the oral cavity, gastrointestinal and genitourinary tracts, even on the skin. Candida is generally harmless, but an overgrowth of the yeast will cause problems.
Normally, the other micro-organisms of the body and the immune system will keep candida at appropriate levels. If the immune system is weakened, candida can cause an opportunistic infection. Cancer and cancer treatment, HIV/AIDS, mononucleosis and other serious illnesses can raise one's risk for developing candidiasis. Hormonal or metabolic disturbances and disorders can also disrupt the body's balance of micro-organisms, and can lead to candidiasis.
Medications are another common cause of yeast overgrowth. Antibiotics may kill off the other organisms keeping yeast in check. Steroid usage has also been linked to increased frequency of candidiasis.
Though it is rare, a person can get candidiasis from an external source. Because of the ubiquity of the organism, particularly in immunocompromised patients, hospital environments are prime breeding grounds for candida. If candida is on medical equipment that comes into contact with mucous membranes or other parts of the body, an infection may result. It is also possible to get candidiasis through genital or oral contact, if one person has an active infection. Even if a person comes into contact with candida from an outside source, it is unlikely to result in an infection, unless the person has a weakened immune system, has been taking antibiotics or has a condition that predisposes him to yeast infection, such as diabetes.