Treating your nails gently can help prevent split fingernails. Consider these simple tips:

• Keep your fingernails dry. Repeated or prolonged contact with water can contribute to split fingernails. Wear protective gloves such as cotton-lined rubber gloves when washing dishes, cleaning or using harsh chemicals.
• Practice good nail hygiene. Keep your fingernails neatly trimmed, and round the tips in a gentle curve. When you use hand lotion, rub the lotion into your fingernails and cuticles, too. Don't bite your fingernails or pick at your cuticles.
• Avoid harsh nail care products. Limit your use of nail polish remover. When using nail polish remover, opt for an acetone-free formula.
• Apply a protective layer. Applying a nail hardener might help strengthen nails.

If your best efforts to prevent split fingernails don't help, ask your doctor or dermatologist for help. Some research suggests that the nutritional supplement biotin might strengthen weak or brittle fingernails.