Tongues reveal qi and blood deficiency.
When it comes to tongues, East and West are not equal. Many doctors in the West ask you to hold out your tongue but it is usually so that they can hold it down with a lollipop stick to get a better look at your tonsills (if you still have them). They might also tut a bit about the horrible coating on it that smacks of a hard night spent networking in the pub. In the East it is a whole different ball game. Tongues are an extremely important diagnostic tool to practitioners of Traditional Asian Medicine. Your tongue will tell them far more than words can say. Colour form and coating on the tongue give vital clues as to the state of the patient's health as well as any ongoing illness and where it may be located. Specifically, the tongue is used to establish the state of 'qi' (energy) and blood which are disrupted during the disease process and this can be seen in the tongue before the illness is fully established. Despite the fact that tongues are important traditional diagnostic aid, very few studies have been carried out to confirm the methodology. A new study has thrown light on the matter.
A Korean group have analysed the tongues of 454 people who did not have any illnesses but 52 of which had a sleep disorder. The colour and form of the tongues of all volunteers were assessed and then 153 returned for further assessment between three and five weeks later. Results showed that the sleep disorder group had paler tongues and the surface coating was more widely distributed when compared to the group with normal sleep patterns. Also the differences between the sleep problem group and the normal group were consistent in the 153 volunteers who returned for the second assessment.
So if you sleep well your tongue is likely to be a good colour with any 'coating' restricted to a small area. If you sleep badly it is more likely to be a paler shade (of grey?) with an overall coating. The Korean team concluded that the state of the tongue can indicated qi and blood deficiency.