The nail plate is formed by the cells in the matrix reproducing. As the
cells multiply they are pushed up before they die and therefore harden.
This process is keratinisation. The nail plate grows at approximately 3mm per month for the fingernail and 1mm per month for the toenail.
The matrix needs a good supply of oxygen and nutrients for the cells to
reproduce.

The growth of the nail can differ due to:

• diet
• illness
• medication
• age
• time of the year (they grow quicker in the summer)
• injury to the matrix or nail bed
• neglect overall.

If cells in the matrix are damaged by illness or injury, the thickness of the
nail plate can vary, such as having a ridge in the nail or overgrowth of
the nail plate. A healthy nail takes approximately six months to grow
from matrix to free edge. It is known that nails grow faster in the summer
than in the winter due to vitamin D production.

A healthy nail should show:

• no inflammation
• a natural sheen
• a supple unbroken cuticle
• a pink glow from underneath the nail bed
• no ridges or spots
• an unbroken free edge.