Yeasts and molds
One of the most common problems I see in practice is associated with the overgrowth of yeast.  Many physicians over the past several decades have linked several forms of yeast to many common health issues.  One common yeast is Candida Albicans. However there are several others and they can cause symptoms such as mood disorders, concentration problems, fatigue, headaches, depression, back pain, digestive problems like bloating and irritable bowel, persistent coughs, itchiness and skin problems.

Perhaps the first doctor to talk about yeast and its associated problems was Dr. William Crook and his book, The Yeast Connection, published in 1986.  Traditional medicine has long relegated yeast problems to those with severely compromised immune systems and not for those people with functional chronic health issues.  It appears that this is one more example of traditional medicine failing to see the immune stress that is appearing all the more frequently in our fast paced,  toxic, and overstressed society.