Yeasts are a subgroup of fungi in the big scheme of categorization. It seems less emotive to discuss the potential for infestation by yeast rather than suggesting that somebody is infected by a fungus!
The most common fungal infection is thought to be Candida, although many other fungi and yeasts live in or on the body surfaces. In their natural place they act as symbionts (both taking and giving some benefit from the host), principally by attacking other, perhaps more dangerous, organisms and also eating available sugars and thereby reducing the amount for other organisms, which, in turn, have their growth inhibited.
Yeast infections are most commonly associated with the vaginal vault, and discharges, discomfort, odours and diseases may result.
Yeast may flourish in the bowel but generally it causes no problems unless the normal bowel flora are reduced and a population overgrowth occurs. The yeasts and fungi of the body tend to produce chemicals that we find toxic and if these increase then symptoms ranging from malaise and tiredness to chronic fatigue syndrome and cancer may evolve.
Yeasts or fungi should not travel around the body and if they are found in the bloodstream they are usually killed off rapidly or filtered out by the liver and kidney. If they do survive they may travel to major organs and cause serious complications. This is much more apparent in those with an immuno-compromised status, such as AIDS.
The orthodox world very rarely takes into account the presence of yeasts and fungi and persistent problems should be assessed by a complementary medical practitioner, who should be reminded of the possibility of yeast infection.
Orthodox cultures of urine and stool rarely look for yeasts and sometimes it is worth specifically asking a laboratory to do so.
A Humoral Pathological Laboratory test (examination of blood samples under high-powered microscopy) may show fungal or yeast spores in any body fluid or excreta or the reaction by red blood cells to the presence of fungal toxins.
Treatment depends on the problem .