Onychoschizia, also known as nail splitting and brittle nails, is a splitting of the free-edged tip of the

nail Nail or Nails may refer to: In biology * Nail (anatomy), toughened protective protein-keratin (known as alpha-keratin, also found in hair) at the end of an animal digit, such as fingernail * Nail (beak), a plate of hard horny tissue at the tip ...

. There is also often a longitudinal split in addition to the separation of

keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ho ...

layers.

Cause

Frequent

hand-washing Hand washing (or handwashing), also known as hand hygiene, is the act of cleaning one's hands with soap or handwash and water to remove viruses/bacteria/microorganisms, dirt, grease, or other harmful and unwanted substances stuck to the hands ...

is the usual cause, but it is also part of normal ageing.

Manicures A manicure is a mostly cosmetic beauty treatment for the fingernails and hands performed at home or in a nail salon. A manicure usually consists of filing and shaping the ''free edge'' of nails, pushing and clipping (with a cuticle pusher a ...

, nail polish and remover,

nail biting Nail biting, also known as onychophagy or onychophagia (or even erroneously onyhophagia), is an oral compulsive habit of biting one's fingernails. It is sometimes described as a parafunctional activity, the common use of the mouth for an activity ...

, and repeated trauma such as typing, can contribute to nail splitting. Dehydration likely plays a role. Nutritional deficiencies that can result in nail splitting include iron, selenium, and zinc. Some

skin diseases A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this sy ...

such as

psoriasis Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by raised areas of abnormal skin. These areas are red, pink, or purple, dry, itchy, and scaly. Psoriasis varies in severity from small, localized patches to complete ...

and

lichen planus Lichen planus (LP) is a chronic inflammatory and immune-mediated disease that affects the skin, nails, hair, and mucous membranes. It is not an actual lichen, and is only named that because it looks like one. It is characterized by polygonal, fla ...

may feature such nails.

Diagnosis

Diagnosis is by its appearance, but sometimes blood tests are required to look for

iron deficiency Iron deficiency, or sideropenia, is the state in which a body lacks enough iron to supply its needs. Iron is present in all cells in the human body and has several vital functions, such as carrying oxygen to the tissues from the lungs as a key ...

thyroid problems Thyroid disease is a medical condition that affects the function of the thyroid gland. The thyroid gland is located at the front of the neck and produces thyroid hormones that travel through the blood to help regulate many other organs, meaning ...

, and

kidney problems Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as eit ...

Treatment

Treatment is by discontinuing nail polish and applying moisturiser. An acceptable alternative is gel nails. Some favourable response has been reported with

biotin Biotin (or vitamin B7) is one of the B vitamins. It is involved in a wide range of metabolic processes, both in humans and in other organisms, primarily related to the utilization of fats, carbohydrates, and amino acids. The name ''biotin'', bor ...

if the person is deficient in vitamin B₇. It is not routinely given.

Epidemiology

It is common among women and occurs in almost a third of newborns.

Other animals

It also occurs in hooved animals such as horses.

References