In normal individuals, there are two longitudinal vessels located on either side of the frenulum under the tongue, known as the sublingual vessels (shé xià luò mài). The mucous membrane under the tongue forms a prominent fold that connects to the floor of the mouth, called the frenulum (shé xì dài). On either side of the frenulum, through the mucous membrane, the lingual veins (shé jìng mài) can be seen in a light blue color, which is referred to in Traditional Chinese Medicine (TCM) as the sublingual vessels (shé xià luò mài). In normal individuals, the vessels (mài) are faintly visible, with a diameter not exceeding 2.5 centimeters. The vessels should not be engorged, tight, twisted, or proliferated, and should be arranged in an orderly manner.
Clinical Significance of the Sublingual Vessels:
If the sublingual vessels (shé xià luò mài) are short and thin, and the surrounding small vessels are not prominent, and the tongue color is pale, this often indicates deficiency of qi and blood (qì xuè bù zú), with insufficient filling of the vessels.
If the sublingual vessels (shé xià luò mài) are thick and engorged, or appear cyanotic, dark red, purplish, or blackish purple, or if the small vessels under the tongue present a dark red or purple network, or if the sublingual vessels (shé xià luò mài) are varicose with nodules of varying sizes resembling purple beads, these changes are all signs of blood stasis (xuè yū). The causes of these changes may include qi stagnation (qì zhì), cold congealing (hán níng), heat accumulation (rè yù), phlegm dampness (tán shī), qi deficiency (qì xū), and yang deficiency (yáng xū).
Director Li Wenxia’s Warm Reminder:The sublingual vessels (shé xià luò mài) are an important basis for analyzing the circulation of qi and blood. It is essential to combine observations of color, thickness, and shape with other symptoms for a comprehensive analysis.
