Nails Ch4 - Estrutura, Distúrbios e Doenças das Unhas

Natual Nail Unit is made up of several parts

  • the nail bed, matrix, nail plate, cuticle, eponychium, hyponychium, specialized ligaments, and nail folds.
  • All the parts of the finger from the tip to the first knuckle are referred to as the natural nail unit.
  • Technically referred to as the onyx.
  • Composed mainly of keratin.
    • Keratin in natural nails is more durable than the keratin in hair or skin.

A normal, healthy nail

  • Is firm and flexible, shiny, and slightly pink in color.
  • Its surface is usually smooth and unspotted, with no splits or deep grooves.
  • Should be whitish and translucent in appearance, with the pinkish or beige color of the nail bed below showing through.


  • UMA ligament is a tough band of fibrous tissue that connects bones or holds an organ in place.
  • Specialized ligaments attach the nail bed and matrix bed to the underlying bone.
    • They are located at the base of the matrix and around the edges of the nail bed.

Factors That Affect Nail Growth

  • Nutrition
  • Exercise
  • A person’s general health

Healthy Nail Growth Facts

  • Grows forward from the matrix and extends over the tip of the finger.
  • Can grow in a variety of shapes, depending on the shape of the matrix. Refer to Figure 4-2.
  • Length, width, and curvature of the matrix determine the thickness, width, and curvature of the plate.
  • Average rate of nail plate growth for adults is about 1/10″ to 1/8″ (2.5 mm to 3 mm) per month.
  • Grows faster in the summer than in the winter.
  • Although toenail plates grow more slowly than fingernail plates, they are thicker because the toenail matrix is longer than the matrix found on fingernails.

Nail Plate Malformation

  • The shape or thickness of the nail plate can change because of damage or infection to the matrix.

Complete replacement of nail plates:

  • Takes about four to six months
  • Toenail plates take nine months to one year

Nail Grooves

  • If nail cells are produced faster, the plate will grow more quickly.
  • If a small portion of the matrix stops making new cells, the nail plate will become thinner and develop a narrow groove.
  • As a normal part of the aging process, parts of the nail matrix begin to permanently slow down production, causing the plate to develop a series of narrow grooves running down the length of the plate.
  • These grooves are not “ridges.”
  • Never file these so-called “ridges,” as this will thin and weaken the entire nail plate.

You are not licensed to diagnose, treat, or prescribe—that constitutes medical practice and cannot be carried out by a nail technician.

  • You must identify whether a client has an unhealthy condition that precludes them from receiving services in a salon; however, you cannot tell a client that they have a specific disease or disorder.
  • Never diagnose, treat, or work on unhealthy skin or nails without written permission from a licensed physician in your state.