Fingernails do not breathe or require external oxygen exchange from the air. This common misconception often arises when people consider the health of their nails, especially in relation to wearing nail polish. The idea that a nail must be periodically left bare to “take a breath” is not supported by the biological function of the nail. Understanding the composition of the nail structure clarifies why atmospheric air plays no role in its metabolic needs.
Anatomy of the Nail Plate
The visible, hard portion of the finger or toenail is known as the nail plate. This structure is composed primarily of keratin, a tough protein also found in hair and the outer layer of skin. The nail plate is made up of multiple layers of tightly packed, flattened cells called keratinocytes. These cells are no longer living tissue, having died and hardened during nail formation.
Because the nail plate is made of dead cells, it has no metabolic function and does not require oxygen or gas exchange. Cutting the nail plate is painless for this reason. The translucent nature of the nail plate allows the pink color of the underlying tissue to show through. This underlying skin, called the nail bed, provides a surface for the nail plate to rest upon.
How Nails Obtain Necessary Oxygen
The living components of the nail unit are located beneath the skin, where growth occurs. The nail matrix is the root of the nail, positioned at the base and protected by the proximal nail fold. This matrix generates new nail cells that are subsequently pushed forward to form the nail plate.
The cells in the matrix and the living tissue of the nail bed require a steady supply of nutrients and oxygen to function. This supply is delivered exclusively through the bloodstream via a dense network of capillaries underneath the nail plate. Oxygen and nutrients reach the actively growing cells internally, bypassing the need for external air exchange. The entire nail unit is nourished from within.
The Effect of Nail Polish and Treatments
While the nail plate does not need to breathe, the concern over continuous nail covering is related to moisture balance and chemical exposure. The nail plate is slightly porous and can absorb water and oils, which helps maintain its flexibility and strength. Constant application of occlusive coatings like polish or enhancements can disrupt this natural hydration process.
A significant factor in nail damage is the frequent use of polish removers, particularly those containing acetone. Acetone is a powerful solvent that rapidly strips the nail plate of its natural oils. This leads to excessive dehydration and brittleness, weakening the nail structure and often resulting in peeling, splitting, and breakage.
Furthermore, prolonged exposure to chemicals, such as those in gel polishes, can affect the underlying structure of the nail. Repeated use has been linked to a reduction in certain amino acids within the nail plate, which contributes to increased fragility. Taking periodic breaks allows the nail to naturally rehydrate and gives an opportunity to assess the health of the underlying nail plate and surrounding skin. These breaks are about rehydration and recovery, not suffocation.