Observation of the Superficial Venule of the Index Finger in Infants

(1) Location
The superficial venule refers to the medial veins of the infant's index finger, which are extended from the branch of the Lung Meridian of Hand Taiyin. The veins are especially obvious in infants under three years of age.
(2) Inspecting method
Holding the wrist of the sick child with the left hand, push lightly the medial veins of the child's index finger several times with the right hand. The light pushing should be directed from the tip of the finger to the palm (i.e., from Mingguan to Qiguan and Fengguan) while making keen observation.
(3) Three gates
From the palm to the tip of the finger, the first knuckle is Fengguan (wind-gates), the second is
Qiyuan (qi-gate) and the last is Mingguan (life-gate).
(4) Differentiation
The normal vein color, is red with a yellow tint, faintly visible at Fengguan. Diseases can be diffierentiated based on the following points:

A. Determining the conditions of the disease according to the location of the veins
The veins only visible at Fengguan usually indicate a mild disease. If they extend to the Qiguan, it shows that the disease is serious. If they extend to the Mingguan, it indicates that the disease is
very serious. The appearance of the superficial veins extending through the three passes toward
the finger nail indicates that the disease is very dangerous.
B. Determining the exterior or interior syndrome according to the depth of the veins
Superficial veins with light color show that the disease is shallow and pertains to the exterior syndrome, while deep veins with dark color suggest that the disease is deep and pertains to the interior syndrome.
C. Determining the cold or heat syndrome according to the color of the veins
The bright red color of the veins indicates that the disease is caused by exogenous pathogenic factors. The purple red color indicates heat syndrome, the blue green color indicates convulsions or pain syndrome or irregular intake of food; the blue purple black color indicates obstruction of the blood vessels by phlegm, food, and heat, suggesting a severe case.
D. Determining the deficiency and excess syndrome according to pale color and deep color of the veins
If the vein color is light and fine, it is mostly due to deficiency of qi and blood; however, if the vein color is deep and rough, it is often due to retention of food in the stomach and intestine.