Onychoschizia describes the common issue of nails splitting or peeling into thin, horizontal layers. This separation of the nail plate layers can signal external damage or an underlying health issue. Understanding the nail’s physical structure and the forces that weaken it is the first step toward achieving stronger, healthier nails.
Understanding How Nail Peeling Occurs
The visible nail plate is composed of numerous layers of densely compacted, non-living cells, primarily made of keratin. These layers are firmly held together by a cellular cement. Peeling occurs when the adhesion between these keratin layers is compromised, particularly at the free edge of the nail.
This loss of adhesion causes the nail plate to horizontally separate, resulting in flaking or splitting. The damage is more noticeable in fingernails because they are subjected to more environmental stress than toenails. Since fingernails grow slowly, taking approximately six months to replace completely, damage that occurred months ago can manifest as peeling today.
External Factors and Environmental Triggers
The most frequent cause of nail peeling involves repeated exposure to external physical or chemical stressors. The constant cycle of wetting and drying is damaging, as the nail absorbs water and swells, only to contract as it dries, repeatedly stressing the bonds between the keratin layers. This is why individuals who frequently wash dishes or have jobs requiring constant handwashing often experience peeling.
Harsh chemicals compromise the nail’s integrity by stripping away its natural protective oils and moisture. Substances like acetone-based nail polish remover, household detergents, and industrial solvents dry out the nail plate, making it brittle and prone to splitting. Physical damage also plays a role, such as using nails as tools to pick or scrape objects, which introduces microtrauma.
Poor manicure practices contribute to peeling, including aggressive filing with a back-and-forth motion or excessive buffing that thins the nail plate. Forcefully picking or peeling off gel polish or artificial nails removes layers of the natural nail. The trauma from these habits creates structural weaknesses that allow the keratin layers to easily separate.
Internal Health and Underlying Causes
While external factors are the most common culprits, peeling nails can reflect a systemic issue. Nutritional deficiencies can disrupt the production of keratin cells; a lack of iron is a common cause that may lead to iron-deficiency anemia and brittle nails. Deficiencies in other micronutrients, such as zinc and B-vitamins like biotin, also impact nail strength and moisture retention.
Age-related changes naturally lead to increased nail brittleness and peeling, as the nail matrix slows its production of new cells and the nail plate loses moisture. Underlying medical conditions can also manifest as nail changes. Thyroid disorders, specifically hypothyroidism, can slow the body’s metabolism and turnover of skin and nail cells, resulting in drier, more fragile nails.
Skin conditions like psoriasis can affect the nail matrix, causing structural abnormalities that lead to pitting, thickening, and peeling. If peeling affects both fingernails and toenails, it is more likely a sign of a systemic issue rather than an external one. A sudden onset of severe peeling, especially with other symptoms, warrants medical investigation.
Treatment and Prevention Strategies
Preventing nail peeling depends on minimizing the cycle of moisture and trauma. Wearing cotton-lined rubber gloves during water-intensive tasks, such as cleaning or dishwashing, protects the nails from excessive hydration and harsh chemicals. Avoid using the nails as tools and limit contact with solvents like acetone.
Regularly moisturizing the nails and cuticles restores flexibility and moisture to the nail plate, preventing the brittle dryness that leads to separation. Applying a hand cream containing alpha-hydroxy acids or a dedicated nail oil multiple times daily is effective. When filing nails, always use a fine-grit file and move in one direction only to seal the nail tip and prevent fraying.
If a nutritional cause is suspected, consulting a physician for blood work to check for deficiencies is advisable. A doctor can diagnose conditions like iron-deficiency anemia or a thyroid disorder and prescribe treatment that addresses the underlying cause of the nail weakness. Seek professional advice if peeling is persistent, accompanied by pain, redness, or discoloration, or if the condition does not improve with home care.