"The lips are also related to the spleen. If the functions of the spleen are normal, the Qi and blood are ample, so the lips are ruddy. If the functions of the spleen are weakened, the Qi and blood will be deficient, so the lips will be pallid. Because the mouth and lips are all related to the spleen, so the book “Ling Shu” says, “The mouth and lips are the organs of the spleen.”"
"Spleen and pancreas condition is reflected externally by the color and tone of the lips: reddish moist lips indicate strong spleen function; pale dry lips are a sign of weak spleen function. The mouth is the spleen's external aperture, and temperamental moodiness is its associated emotion. The Chinese term for 'bad temper' is 'bad spleen energy', a psychophysiological association also reflected in the English term 'splenetic'." -http://www.wingmakers.co.nz/Organs%20Of%20The%20Earth%20Meridian.html