Nails, like hair, are formed of layers of keratin, a fibrous protein. They consist of a matrix which is deeply rooted in the finger and produces the keratin cells necessary for their development. The visible part of the nail is called the nail plate. Each day nails grow approximately 1 mm. Sometimes the nails become fragile because of daily physical or chemical stress. So they become soft and brittle and peeling. Ridges--more or less parallel grooves along the width or length of the nails--form. Finally, afflictions such as mycosis can occur in the nail. Onychomycosis, or mycosis of the nail, is characterised by a thickening of the nail and change in nail colour.

There are several factors that cause fragile nails, starting with frequent or extended contact with water. Indeed, because the nail structure is porous by design, water makes it more vulnerable. It causes the layers of keratin to swell, which pulls them apart and dries them out. There are also other causes of nail fragility:  

• Ageing
• Genetic predisposition
• Dermatitis (psoriasis, etc.)
• Onychophagia (nail biting)
• Use of detergent agents
• Cold or excessive heat
• UV rays
• Aggressive manicures

To avoid fragile nails, follow these tips:  

• Thoroughly dry your hands and nails after each washing
• Thoroughly moisturise your hands and nails, especially when the weather is very cold or dry
• Protect your hands with gloves when you use detergents
• Eat a balanced diet because deficiencies weaken the nails
• Avoid biting your nails or nibbling the skin around your nails
• Avoid ill-adapted cosmetic products (overly abrasive nail varnish remover, etc.)