Brittle fingernails are caused by trauma, overexposure to harsh solvents, recurring exposure to liquids, malnutrition or an underlying health problem, according to NYU Langone Medical Center. Brittle nails are also a normal effect of aging, according to MedlinePlus.
Health conditions that sometimes cause brittle fingernails include thyroid disorders, lung conditions, Siogren’s syndrome, skin diseases or endocrine disorders, according to NYU Langone. Selenium poisoning is also a cause.
It is possible to prevent some damage to the nails by wearing protective gloves and using gentler solvents, according to NYU Langone. Additional tips for nail health include keeping the nails short, avoiding nail polish, and using an emollient cream after bathing or washing, according to MedlinePlus.