Nail cap divided into two layers is mostly seen in bad habits, fungal infections, and nail malnutrition. 1. Bad habits: Long-term bad habits, such as frequent rubbing of the nails and frequent manicures, lead to thinning of the nails, which are prone to layering and splitting of the nails. 2. Fungal infection: Fungus invades the nail plate and nail bed, which may lead to changes in the color and texture of the nails, for example, thickening, yellowing, and layering. 3. Nail malnutrition: Long-term poor dietary habits, often partiality and picky eating, excessive weight loss, resulting in malnutrition, will have an impact on the growth of nails, resulting in nail malnutrition, easy to appear nail layering. In addition, certain systemic diseases such as heart disease, chronic liver disease, kidney disease, and respiratory disease can also cause nail layering. It is recommended to reduce adverse stimuli, pay attention to nutritional supplementation, and if necessary, go to the dermatology department of the hospital for relevant tests and give appropriate medication to treat the symptoms.