My research, which includes examining specimens from many individuals, shows a very diverse selection of problematic fungi involved in their ailments.
My interest is in parasitic complications, but I do find a large group of individuals with blood-borne fungal metabolites.
The concept many people have come to accept is "candida" becomes over-grown in the gut, and causes health issues.
This is a misconception, according to my personal experience observing the phenomenon.
Most of the time it is not candida at all, and in many cases it is other types of fungi, some common others not.
The best way to identify the species, is by isolating macrophages from the blood, which contain gammetes or "spores" that have not been digested and destroyed by the white cells.
Then, these components are grown under the correct conditions. The "spores" which will develop over time can be morphologically identified. This is predicated on the experience of the technician, and access to comprehensive image data bases.
If this fails, PCR identification is the best and most accurate option.
The way fungi infiltrate the host, is similar to protozoa. Many times, it's easily confused.
The fungi usually originate in the gut, but not always in their mature form. The results of the infiltration will often cause the activation of gut immune factors, and areas where mucus membranes are involved. This stimulates mast cell degranulation, and histamine production [along with tons other things].
This action causes dehydration and disturbs the microbiome of the gut, and skin in some cases.
Of course, there may be very slight fluctuations in the PH of certain areas of the body, causing other problems to develop.
This information is strictly based on my own studies, and is far from giving a full picture of systemic complications from fungi\microbes of any type. Shroom