I was talking with someone yesterday about her tongue fissures (cracks in the surface of the tongue). She has been dealing with some really nasty ones, while at the same time handling some other health issues which her doctors are treating with prescription medications. Her doctor recommended using toothpaste with the fewest possible additives. In the brief time time that we had to talk, I suggested that she Google “tongue fissures Chinese medicine diagnosis” and “probiotics yeast”. With more time in a different context, I would have liked to have told her how Candida yeast can cause thrush, a very likely cause of the coating she also had on her tongue. Many prescription medications disrupt the balance of the intestinal tract, which can then be overpopulated with Candida. Candida is a form of yeast which can proliferate throughout the body, causing a number of strange symptoms including a yucky coating of the tongue, skin rashes, sugar/carbohydrate cravings, and diarrhea.
Here is the link I had hoped to find while she and I were talking:
http://beyondwellbeing.com/herbs/tongue-diagnosis.shtml
Just like the iris of the eye, the tongue is an amazing visual roadmap to the health of the body. When you go to an acupuncturist, herbalist, naturopath, osteopath, or other integrative medical practitioner/doctor, one of the first things they will do is ask to see your tongue. They will look at it for a few seconds and be able to tell quite a bit about what’s going on with your body. In fact, if you’ve had trouble getting well following your regular doctor’s instructions, visit one of the healers listed above and see what they have to say.
Great links:

My quick reply is Yeast. You can catch it from your mother at birth, and I don’t see why it wouldn’t be possible and/or likely for a fetus to have a systemic infection if its mother does.
The shapes, patterns, and locations of patches and of the tongue itself also give more information about what’s happening in the body. If the sides of your tongue are “scalloped”, it means that your intestines are in wimpy shape (can happen easily). That can be from a combination of diet, yeast imbalance, and lack of physical exercise. Walking is a very healthy way of addressing this.
Want to email me a picture of your tongue? We can see what’s going on.
I found your articles about using the eyes and the tongue to diagnose health very informative. I was born with a “geogrphic tongue” – any info about that. It seems to have gotten better as I have gotten older.