How Do Split Nails Happen—and What Can You Do To Fix It

Nutrients like iron, zinc, biotin (vitamin B7), and selenium help keep your nails strong and healthy. If you are deficient in any of these nutrients, you can develop brittle nails that start to split. Brittle nails are especially common in people with iron deficiencies.

Nail Splitting (Onychoschizia)

Onychoschizia, commonly known as nail peeling or nail splitting, is a condition that causes horizontal splits (across the width of the nail) in the nail plate. Onychoschizia may be seen along with another common nail condition called onychorrhexis, which involves longitudinal (across the length of the nail) splits or ridges in the nail plate. These conditions alone or together are sometimes simply called “brittle nails.” Frequent wetting and drying of the hands is the most common cause of brittle nails. Brittle nails may also be caused by nail cosmetics (hardeners, polish, polish removers / solvents), nail procedures, and occupational exposure to various chemicals (alkalis, acids, cement, solvents, thioglycolates, salt, sugar solutions). Nail injury may also cause the development of brittle nails. Brittle nails may also occur due to underlying medical problems such as gland (endocrine system) diseases, tuberculosis, Sjögren syndrome, and malnutrition. People with other skin diseases, such as lichen planus and psoriasis, as well as people taking oral medications made from vitamin A (retinoids), may also develop brittle nails.

Who’s At Risk?

Brittle nails are fairly common, affecting nearly 20% of the population. They are most frequent in women and older adults. People in occupations requiring frequent wetting and drying of the hands or who work with chemicals are also at increased risk for brittle nails. Horizontal splitting of the thumbnails and big toes is quite common in newborns, affecting about 1 in 3 newborns. Fingernail and toenail splitting in children up to age 2 years is also seen, and it is thought to be because their nails are so thin. Thumb sucking can also be a contributing factor in nail splitting.

Signs and Symptoms

• The fingernails and toenails can be affected. There may be a single horizontal split between layers of the nail plate at the growing end or multiple splits and loosening of the growing edge of the nail plate (where the end of the finger or toe is attached to the nail itself).
• There may be horizontal nail splitting along with longitudinal ridging or splitting.
• Splitting or ridging of the nails may be seen in people with certain conditions such as psoriasis or lichen planus or in people who take oral medications made from vitamin A (oral retinoids).

Self-Care Guidelines

To help improve brittle nails and nail splitting and peeling:

• Reduce how often you wet and dry your nails.
• Wear plastic or rubber gloves over thin cotton gloves while doing all housework, including food preparation.
• Keep the nails trimmed short.
• Apply thick moisturizers (eg, CeraVe Moisturizing Cream) or petroleum jelly (eg, Vaseline) to improve nail hydration.
• Nail-hardening agents containing formaldehyde may increase nail strength, but they should be used cautiously, as they can cause brittleness and other nail problems. Apply these hardeners only to the free edge (growing end) of the nail.
• Acrylate-containing hardeners are also effective, but they may cause an allergic reaction in the skin.

Treatments

Your medical professional will first want to determine the cause of your brittle, peeling, or splitting nails, such as an underlying medical condition or nail disease. If there is a medication causing your nail issues, your medical professional can help determine if another medication may be an appropriate substitute.

Visit Urgency

Brittle, peeling, or splitting nails may be merely a cosmetic problem, but see your medical professional if it becomes bothersome or there may be an underlying cause such as a medical condition or a medication.

Trusted Links

• MedlinePlus: Nail Diseases
• Clinical Information and Differential Diagnosis of Onychoschizia

References

Bolognia J, Schaffer JV, Cerroni L. Dermatology. 4th ed. Philadelphia, PA: Elsevier; 2018.

James WD, Elston D, Treat JR, Rosenbach MA. Andrew’s Diseases of the Skin. 13th ed. Philadelphia, PA: Elsevier; 2019.

Kang S, Amagai M, Bruckner AL, et al. Fitzpatrick’s Dermatology. 9th ed. New York, NY: McGraw-Hill Education; 2019.

Disease Groups: Common Nail Problems

Last modified on June 18th, 2024 at 12:50 pm

How Do Split Nails Happen—and What Can You Do To Fix It?

Carley Millhone is a writer and editor based in the Midwest who covers health, women’s wellness, and travel. Her work has appeared in publications like SELF, Greatist, and PureWow.

Published on January 25, 2024
Medically reviewed by

Brendan Camp, MD, FAAD, is a double board-certified dermatologist.

A split nail (onychoschizia) is a vertical or horizontal crack through the fingernail. The nail may also feel soft, thin, or brittle. Injury, harsh chemicals, psoriasis, nail fungus, or vitamin deficiencies can all lead to splitting nails.

Women experience split nails twice as often as men, and split nails are more common in people 50 and older. You can treat a split nail, but if an underlying health condition is causing nail splitting, you’ll need to treat the condition first. Severe and repeated nail splits can increase your risk of infection and permanent nail bed damage if left untreated.

What Causes a Split Nail?

A split nail can be caused by various underlying health conditions or damage to the nail.

Nail Fungus (Onychomycosis)

When fungus enters the nail through small nail cracks or the skin surrounding the nail, this can cause a fungal nail infection. The infection can make nails fragile, discolored, and misshapen. As fungi grow, they damage the nail, leading to nail splitting or separation from the nail bed (the fleshy part underneath the nail).

People with diabetes, a weakened immune system, or nail injury are more likely to get a fungal nail infection. People with diabetes or weakened immune systems are also more likely to get bacterial nail infections.

Aging

As you age, your nails grow more slowly and can become brittle and discolored. As a result, the tips of the fingernails may start to crack and split down the nail. Aging nails can also become thick and form ridges that split.

Nutrient Deficiency

Nutrients like iron, zinc, biotin (vitamin B7), and selenium help keep your nails strong and healthy. If you are deficient in any of these nutrients, you can develop brittle nails that start to split. Brittle nails are especially common in people with iron deficiencies.

Pregnancy

Your nails can become brittle and prone to nail splits during pregnancy. Research shows pregnancy-related nail splitting is more common during 29-42 weeks of pregnancy.

If you’re pregnant and have a split nail, you may have an underlying iron deficiency. Pregnant people are more likely to experience iron deficiency anemia because the body makes more blood to help the baby grow. This increase in blood volume requires more iron to make healthy red blood cells, which can lead to iron deficiency anemia.

Nail Psoriasis

Psoriasis is typically known as a skin condition that causes itchy, scaly patches of skin. However, psoriasis can also affect your nails. Nail psoriasis can cause pitting, discoloration, separation, crumbling, and splitting.

About 10-55% of people with plaque psoriasis develop nail psoriasis. Nail psoriasis can also appear a few years after someone’s first psoriasis flare.

Too Much Moisture or Chemical Exposure

Excess moisture can weaken your nails, causing them to become brittle, soft, and prone to splitting. Too little moisture can also make nails dry and brittle. Your nails may encounter too much moisture from doing dishes, washing your hands frequently, or cleaning.

Harsh solvents and chemicals in cleaning supplies and nail polish can dehydrate your nails, causing the nails to separate and crack. People who regularly have their nails done and use nail polish remover are also more prone to dry nails and cracks.

Nail Injury

Snagging your nails on fabric, smashing your fingers in a door, or cutting your fingernail with a sharp object can all cause nail splitting. In addition to a vertical or horizontal split in the nail, you may tear away part of the nail, feel throbbing pain, or notice bleeding underneath or around the nail.

Nail Picking or Biting

Picking or biting your nails can also damage them—making the nails brittle, uneven, and prone to splitting. People who bite their nails can damage the tissues underneath and surrounding the nail, causing pain and bleeding. Nail biting or picking is often a side effect of anxiety or stress.

What Does a Split Nail Look Like?

A split nail often looks like a vertical crack starting from the tip of the nail and moving toward the cuticle (the band of tissues near the base of the nail). These splits are often surrounded by white discoloration—or some redness if the nail bed is bleeding. Cracks can also occur horizontally across the top of the nail or in several nail layers. You can have one or several cracks on a single nail.

Split nails are often brittle and break easily. They may also feel soft, almost squishy, and thin when touching them. Nail splits can also cause the nail to start separating from the nail bed, causing parts of your nail to fall off.

How to Treat a Split Nail

If you have a split nail, you can take some steps to repair the broken nail at home:

• Use nail clippers to trim off any nail extending past the nail bed.
• If your nail is split down toward the cuticle or across the nail bed, apply nail wraps to help strengthen the nail and prevent more breakage. Self-adhesive silk nail wraps can be cut down to fit the exact size of your nail split and secured with gel nail resin.
• If the split is less severe, try applying nail polish with nylon fiber to help strengthen the nail.

If your split nail is caused by a fungal infection, nutrient deficiency, or psoriasis, you’ll need to see your healthcare provider for treatment. Splits caused by nail fungus will require anti-fungal medication to kill the infection and prevent future breaks.

If you have psoriasis, your provider may recommend treating nail splits with a topical corticosteroid, retinoids like tazarotene (Fabior), or vitamin D derivative treatments like calcipotriol (Calcitrene). They may also prescribe a biologic medication for psoriasis, which can help treat both the skin and nails.

Your provider can also test you for nutrient deficiencies that can cause nail splits and help provide a treatment plan.

If part of your split nail separates from the nail bed and falls off, it will take seven to 10 days for the underlying nail bed to heal. However, it takes even longer for the actual nail to grow back. Fingernails take about four to six months to grow back. Toenails can take about a year.

Potential Complications

Severe and untreated split nails can cause permanent damage to the underlying nail bed and tissues that help nails grow. This can cause the nail to grow back abnormally and cause permanently misshaped nails.

If your split nails don’t resolve on their own, or you have multiple nails with splits, you may have an underlying condition or infection that needs treatment from a healthcare provider. Other signs you may have a condition or infection needing treatment include:

• Built-up debris under the nail
• Nails that feel soft, dry, and powdery
• Thick brown or yellow nails
• Crumbling nails
• Small dents in the nails (nail pits)
• Streaks of blood underneath the nail
• Nail that completely separates from the nail bed

How To Prevent a Split Nail

You can often help prevent nail splits with a good hygiene routine. Some simple ways to keep your nails healthy and avoid a split nail include:

• Keep your nails clean and dry. Cleaning your nails and avoiding excess moisture can help prevent unwanted fungal infections.
• Trim your nails short. Cut nails straight across with clippers and slightly round the tips of the nails for optimum strength. Short nails also help avoid breakage.
• Avoid walking barefoot in public areas. Wearing sandals in damp areas like public pools and locker rooms can help prevent unwanted nail infections from lingering fungus.
• Don’t share nail tools. Keeping your nail files and clippers to yourself helps prevent passing fungal infections.
• Choose clean and licensed nail salons and spas. Visiting professionals who create a clean environment and use sterilized tools can help you avoid nail infections and injury.
• Wear protective gloves when cleaning. Wearing gloves while you clean with chemicals or immerse your hands in water can help protect your nails from drying out or becoming too soft.
• Try to quit biting and picking your nails. Keeping your nails short, getting regular manicures, identifying stress triggers, or applying bitter-tasting nail polish may help you kick the habit.

Other Ways To Improve Nail Care

Additional supplements, dietary changes, and nail care may also help keep your nails healthy, including:

• Eating biotin-rich and collagen-rich foods: Your body needs sources of biotin and collagen for healthy nails. Eating organ meats, eggs, fish, meat, seeds, and sweet potatoes provides a good source of biotin. Collagen is in animal bones, skin, and ligaments—found in chicken, pork, beef, fish, bone broth, and gelatin. Your body can also boost collagen production from amino acids in plant foods like quinoa, mushrooms, legumes, and beans.
• Taking biotin supplements: Limited research shows biotin supplementation improves nail health, and many studies are small and self-reported. Still, a small study found that taking 5–10 milligrams (mg) of biotin daily for three to six months helped participants improve nail firmness and hardness. Just note that biotin deficiencies are rare, and biotin supplements don’t appear to improve nail health or growth in healthy people.
• Taking collagen supplements: Research on the effectiveness of collagen peptides for nail strength is limited. However, a small study found taking 2.5 grams (g) of bioactive collagen peptides daily for 24 weeks improved nail growth and reduced nail cracks and chips.
• Moisturizing your nails: Studies show applying nail moisturizers with alpha hydroxy acids (AHA), glycerin, or lanolin can help strengthen brittle nails. Lanolin is an occlusive (protective barrier) that helps hold in water. AHAs and glycerin are humectants (moisturizing agents) that help increase the nail’s water content to amp up moisture.
• Applying a nail hardener: Also called nail strengtheners or fortifying nail builders, these products use silicone to help restructure fragile nails. Some new nail strengtheners also help improve nail moisture and keratin content (the protein that forms your nails).

A Quick Review

Split nails can happen from injuries, fungal infections, or underlying conditions like nail psoriasis. Your nail may split in a single white line vertically or horizontally, or split into layers. If you split your nail, you can often treat it at home by trimming the nail and covering the split with nail wraps and nail polish.

See your healthcare provider for treatment if your nails don’t improve or you have severe pain, separation, or discoloration. You may need anti-fungal medications, dietary supplements, or psoriasis treatments to heal and prevent split nails. If you’re otherwise healthy, keeping your nails short and clean will typically help prevent nail splits.