What can affect the shape or thickness of the nail plate?

The shape and thickness of the nail plate are significantly influenced by the health and condition of the nail matrix, which is the tissue under the base of the nail where new nail cells are produced. When the matrix sustains damage, it can lead to abnormalities in nail growth, resulting in nails that are thinner, thicker, or distorted in shape. Since the matrix is responsible for generating the cells that form the nail plate, any injury or disruption can directly impact the nail's appearance and structural integrity.

Other options, while they may have various effects on nail health and appearance, do not have the same direct impact on the shaping or thickness of the nail plate at the cellular level as damage to the matrix does. For instance, cuticle care techniques largely relate to the maintenance of nail hygiene but do not alter the nail plate structure itself; exposure to water can cause temporary changes to the nail's texture but usually doesn't affect its inherent shape or thickness in the long term; and nail polish usage might influence aesthetics but does not change the physical characteristics of the nail plate. Thus, damage to the matrix is the decisive factor when considering the effects on the shape or thickness of the nail plate.