Medically reviewed by Dr. Tom Biernacki, DPM
Board-certified podiatric surgeon | Balance Foot & Ankle, Howell & Bloomfield Hills, MI
Last reviewed: May 2026
Onychorrhexis — brittle nails with longitudinal ridging and splitting — can result from simple dehydration or from systemic conditions that require medical evaluation, and the specific nail change pattern that distinguishes the two prevents unnecessary nail treatments. Call (810) 206-1402 — expert podiatric care across Michigan.
Onychorrhexis refers to brittle nails with longitudinal ridging and a tendency to split or break in strips along the ridges. It differs from Beau lines (transverse grooves) and onychoschizia (lamellar splitting at the tip). Onychorrhexis affects the entire nail plate and typically has a systemic, nutritional, or occupational cause. Treatment targets the underlying etiology first; topical nail strengtheners are adjunctive.
Onychorrhexis Causes by Category
| Category | Specific Causes | Associated Findings | Diagnostic Clue |
|---|---|---|---|
| Systemic disease | Hypothyroidism, anemia (iron deficiency), peripheral artery disease, lichen planus, Darier disease | All nails affected; systemic symptoms present | Check TSH, CBC, ferritin; lichen planus shows pterygium |
| Nutritional deficiency | Iron, biotin, protein, zinc, calcium deficiency | All nails; may have hair brittleness simultaneously | Dietary history; serum ferritin most commonly low |
| Occupational/chemical | Repeated water exposure; detergents; acetone; nail polish remover; harsh chemicals | Fingernails more than toenails; occupational pattern | Nail involvement correlates with chemical exposure duration |
| Dermatologic | Psoriasis, lichen planus (nail only) | Psoriasis: pitting, oil spots; LP: pterygium, scarring | Nail biopsy if lichen planus suspected; dermatology referral |
| Aging (physiologic) | Normal age-related change after age 50 | All nails; no systemic cause found | Diagnosis of exclusion; rule out hypothyroidism and nutritional causes first |
Onychorrhexis Treatment by Evidence Level
| Treatment | Mechanism | Evidence Level | Notes |
|---|---|---|---|
| Treat underlying systemic cause | Correction of thyroid function, iron repletion, nutritional supplementation | High — nail improvement follows systemic correction | Allow 6 months for full nail cycle turnover after correction |
| Biotin supplementation (2.5-5 mg/day) | Cofactor in nail keratin synthesis; increases nail plate thickness | Moderate — controlled trial data show 25% plate thickness increase | Only effective when biotin-deficient; does not help in deficiency-absent cases |
| Nail hardener / strengthening lacquer | Formaldehyde-based: cross-links keratin (avoid long-term); non-formaldehyde: film-forming proteins | Low to moderate — symptomatic improvement; does not address cause | Formaldehyde hardeners can worsen brittleness with overuse; cycle use |
| Emollient nail soaking + urea 20-40% cream | Increases nail hydration and flexibility; reduces micro-fractures | Moderate for hydration-related brittleness | Soak nails 5 min in warm water; apply urea cream; cover overnight |
| Minimize chemical exposure | Eliminate nail-dehydrating agents; wear gloves for wet work | High for occupational causes | Acetone-free remover; gloves for dishwashing; limit water immersion |
At Balance Foot & Ankle in Howell and Bloomfield Hills, we evaluate toenail disorders including onychorrhexis as part of comprehensive nail assessment — distinguishing systemic causes from local nail plate problems. Call (810) 206-1402.
American Academy of Dermatology: Nail Conditions
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Doctor Answer
What is onychorrhexis and how is it treated?
Onychorrhexis is a condition where the nails develop longitudinal ridging and splitting, often from aging, nutritional deficiencies (particularly iron or biotin), hypothyroidism, or chronic dehydration. Treatment addresses the underlying cause — nutritional supplementation, thyroid management, and topical nail strengtheners. Moisturizing the nail plate with oils and avoiding harsh chemicals and acetone polish remover also helps reduce brittleness and splitting.
Dr. Tom Biernacki, DPM is a board-certified foot & ankle surgeon (ABFAS & ABPM) at Balance Foot & Ankle Specialists in Southeast Michigan. With over a decade of clinical experience, he specializes in heel pain, bunions, diabetic foot care, sports injuries, and minimally invasive surgery. Dr. Biernacki is a member of the APMA and ACFAS, and his patient education content on MichiganFootDoctors.com and YouTube has made him one of the most-followed foot & ankle educators on YouTube.