Up to the age of three, an inspection of the index finger of an infant may give some indications of the condition of the child. The index finger is divided into three parts, from the metacarpo-phalangeal joint to the proximal interphalangeal joint, from the proximal interphalangeal joint to the distal interphalangeal joint, and from there to the tip of the finger. After stroking the palmar aspect of the index finger of the child a few times from distal to proximal, the practitioner will pay attention to the appearance of colors or veins in these three regions. The first (proximal area) is called the gate of wind. If an abnormal appearance of a vein or colors is observed in this area, a more superficial condition may be suspected. If these signs appear in the second area, referred to as the Qi gate, the disease is expected to have progressed more internally. The appearance of a vein or abnormal color in the most distal area, called the gate of Ming, implies that the interior with its Zang–Fu are affected and the condition is quite serious.
