1. Nail diagnosis

Information about the health of the body can be obtained by observing, touching, pressing, and moving the nail, subungual tissue (nail matrix) and the conjunction of nail and skin. The value of nail diagnosis is briefly discussed as follows:

1) Normal nail:

Shape: The normal nail is an elliptic, ball-shaped plate with a small vertical and horizontal curvature. It has the proper thickness, an elastic hardness, a concealed pink color and a smooth, shiny, and semi-transparent appearance. The lunar zone is normal. The nail fold at the junction of the nail root and skin is red, smooth, soft and regular. There are no ridges or fissures on the surface of the nail plate and no stripes or petechiae on the subungual tissue. The soft red color may be quickly restored after pressure is applied and then released from the nail plate (Fig. 4-5).

Indication: These indicate that both qi and blood are sufficient, meridians are clear, the function of the organs is normal, the body is healthy, and vital energy is plentiful.

2) Long nail :

Shape: The nail plate is bright and clean, but longer than normal and scattered with fine vertical grooves. The subungual tissue is bright, but slightly pale, and the lunar zone is normal. Sometimes, a small hangnail may appear in the nail groove (Fig. 4-5).

Indication: This indicates the impairment of respiratory function, dysfunction of stomach and intestine, and an unsteady emotional condition.

3) Short nail:

Shape: The nail plate is shorter than normal and occupies only one-third of the distal phalanx of finger. The color of the nail plate and subungual tissue is normal and the lunar zone is very small or hiddened underneath the nail fold (Fig. 4-5).

Indication: People with short nails are healthy and robust with a good bursting strength (strength instantly released). Their emotional condition is unstable. People with short nails are easily annoyed, quick to anger, and susceptible to hyperten-sion and liver disease.

4) Round nail:

Shane: This is a semicircular nail with its peripheral borders coincident with the edge of the distal phalanx, except the proximal border. The nail fold is irregular, but the color of the nail plate and subungual tissue is normal (Fig. 4-6).

Indication: People with round nails have a strong physique, good bursting strength, and an unstable emotional condition, and are susceptible to vertigo, migraine, and metabolic diseases.

5) Oval nail:

Shape: This nail is a small oval plate with normal color and some fine vertical lines visible against the light. The color of subungual tissue is normal and the lunar zone is also normal (Fig. 4-6).

Indication: People with oval nails are healthy, but their emotional makeup is unstable with strong unsatisfied desires. They are susceptible to stomach diseases, headache, and insomnia.

6) Narrow nail:

Shape: The nail plate is narrow and occupys only one-third the width of the distal phalanx of finger. The skin fold beside the nail is almost as wide as the nail plate. The nail color is uneven and with careful observation some fine horizontal lines are visible on the nail plate. (Fig. 4-6).

Indication: People with narrow nails are susceptible to cervical and lumbar spinal column diseases, hyperosteogeny, and heart disease.

7) Broad nail:

Shape: This nail plate is broad with a much wider free margin. The nail root is depressed and the lunar zone is a narrow stripe. Some vertical and horizontal lines are visible against light. The nail color and subungual tissue are normal (Fig. 4-7).

Indication: People with broad nails are susceptible to thyroid gland dysfunction and sterility.