As a medical doctor, I am guided by a system of thought that is supported by research, common sense, or at least by experience. Patients come to me for advice, and I make sure that my answers instill confidence, build trust, and lead to positive results.

However, I’m often asked about subjects where I find no support from my training, the medical literature, or personal experience. One such topic is Candida.

What is clear and well researched is that Candida is a genus of yeast and is the most common cause of fungal infections. Many species are completely harmless and live in and on humans. Exposure to Candida is so common that tests that measure a response to Candida can be used to confirm that the immune system is working properly. Candida is a normal member of our gut flora, among trillions of microscopic yeasts and bacteria.

Sometimes Candida becomes so numerous that it causes a yeast infection, especially on the surface of the skin in such warm moist places as beneath the breasts, armpits, the groin, nail beds, and, for those who are very overweight, in folds of skin of the lower abdomen. Another common site for fungal infections is the mouth, where the infection is called oral thrush. Candida is also responsible for the most common vaginal infection. These infections become more common with age, diabetes, diseases causing suppression of the immune system (such as AIDS, cancer or critical illness), use of oral steroids, and heavy use of antibiotics.

It’s possible, but rare, for Candida to get into the bloodstream and spread throughout the body. This is known as candidemia, and can happen if someone has a very weakened immune system and a yeast infection that has gone untreated. Symptoms usually include high fever and chills. It is seen most often in people who have been in the hospital, and represents a leading cause of bloodstream infection and death among hospitalized patients.

Despite the fact that Candida can cause serious problems, it is still normal and universally found among healthy people, and belongs in our bodies. Yet since around the 1980’s, there has been much discussion about the purported condition of chronic candidiasis. This has absolutely no support among mainstream medicine. The concept became a social phenomenon in 1986 with the publication of The Yeast Connection by Dr. William Crook. In his book, he proposed that systemic candidiasis, or Candida hypersensitivity, was responsible for a long list of common conditions and non-specific symptoms including fatigue, sexual dysfunction, asthma, and psoriasis. Dr. Crook conducted no research to support his claims. He managed to bypass research, peer review, and scientific consensus, going directly to public promotion! This concept was further bolstered by a 2009 Huffington Post blog by Kim Evans, who claimed that 90% of the population has a problem with Candida overgrowth. She speculated that Candida overgrowth could be the root cause of hundreds of different problems in the body.

Today, Candida hypersensitivity remains a popular condition among some alternative practitioners. The American Academy of Allergy, Asthma and Immunology states that it is speculative and unproven. They point out that some of the proposed treatments offered can be dangerous.

I am committed to practicing medicine that is supported by science. So, my recommendation is to look elsewhere for an explanation of your symptoms. At this time, medical science believes that practically all of us have candida growing in our intestines…and that it is not harmful.

Paging Dr. Frischer: Candida