Of course the sides of the tongue reflect the state of the Liver but there are circumstances when they reflect the state of the Spleen.
The area on the sides reflecting the Liver is long and rather narrow. By “long” I mean that it extends almost from the root to near the tip. A redness of this area is very common and it indicates Liver-Heat.
|Red sides, Liver area|
|Swollen sides, Liver area|
The area on the sides reflecting the Spleen differs from that reflecting the Liver in two ways:
1) it is less long, being concentrated in the middle section of the tongue (Middle Burner);
2) it is wider.
A common change in this area is a swelling which indicates Dampness in the Spleen. It also is often pale, indicating Spleen deficiency. If it is pale and swollen it indicates Spleen-Qi deficiency leading to Dampness. The Spleen area may also be red indicating Spleen-Heat.
|Swelling Spleen areas|
|Redness Spleen areas|
Compare this redness on the sides with the redness in the Liver areas above (first picture)
The chest/breast/ area is completely different being confined to a relatively small area between the middle section of the tongue and the tip.