All lessons Module 1: Tongue Lesson 5
The coating
What does the coating tell you about the Stomach and about the pathogen?
After this lesson you can read the coating along five axes (thickness, colour, root, texture, distribution), use thin white as the baseline, establish by looking, and if needed by light scraping, whether the coating is rooted, tell sticky from grainy, interpret a peeled coating, a geographic tongue and coating on one half, and recognise what lies on the tongue but is not coating.
Know by heart
- Five axes. Thickness, colour, root, texture, distribution; mnemonic: how much, what colour, firm or loose, how it feels, where it lies.
- Thickness. If the muscle shows through, it is thin. No coating: Stomach-Qi or Yin is running out. Thin: normal, or a beginning. Thick: a pathogen, stronger and deeper.
- Colour. White: Cold, or normal if it is thin. Yellow: Heat, the darker the hotter. Grey or black: extreme, wet is Cold and dry is Heat; check for staining first.
- Root. Rooted: grows out of the tongue and does not come away; the Stomach-Qi is working. Rootless: lies on top and scrapes off; Stomach-Qi and Yin are running out; mnemonic: firm, loose, bare, mirror: four steps to an empty Stomach.
- Texture. Sticky: attached, fine and shiny: Dampness or Phlegm. Loose and grainy: coarse, like cottage cheese, wipes off: retained food, with Stomach-Heat.
- Distribution. Front: Upper Burner, start of an Exterior pattern. Centre: Spleen and Stomach. Root: Lower Burner. One half: Shaoyang, or Liver and Gall-Bladder. Peeled in the centre: Stomach-Yin; on the root: Kidney-Yin.
- What is not coating. White patches that wipe off, leaving a red base: thrush. White or red that does not wipe off and persists: a dentist, or a GP or primary care doctor. Black and hairy: medicines and smoking. Coloured: ask what has been in the mouth.
The rest of this lesson is reference.
Three practice questions from this lesson
Along which five axes do you read the coating?
- Thickness, colour, root, texture, distribution
- Colour, shape, movement, signs, area and underside
- Thickness, colour, moisture, pulse, history
Answer: Thickness, colour, root, texture, distribution. How much, what colour, firm or loose, how it feels, and where it lies. The moisture of the tongue is a separate look (lesson 6).
A thick yellow coating that is firmly attached, compared with a thin white coating that lies on top as if sprinkled on. Which is more favourable for the Stomach?
- The thick, rooted coating
- The thin, rootless coating
- They are equally favourable
Answer: The thick, rooted coating. Rooted means the Stomach-Qi is still working, even when a pathogen is present. Rootless means the Stomach itself is becoming exhausted.
Case. Woman, 82, ill and exhausted for months, hardly eats. Her coating comes away at once with light scraping; underneath, the tongue is smooth and red.
- Stomach-Qi and Yin are running out: a serious sign
- The pathogen has gone: the tongue is clearing and recovering
- A normal tongue for her age
Answer: Stomach-Qi and Yin are running out: a serious sign. Rootless, with a smooth red tongue underneath: the Stomach is no longer making coating. In an exhausted older person that is serious; coordinate with her doctor.
The rest of this lesson
In the course you get the step-by-step explanation with illustrated tongues and animated pulse models, 17 case-based practice questions, 21 spaced-repetition flashcards, the pitfalls, the bridge to physiology and the visual trainer. This lesson belongs to module 1: Tongue.