Onycholysis (Nail Separation) - Symptoms, Causes & Treatment
Medically reviewed by Dr. Anand S. Urhekar, MD, MD Pathology, Clinical Advisor · Last updated July 2026
Painless separation of the nail plate from the nail bed, starting at the free edge and progressing backwards, which makes the detached area look white, yellow or green. Causes include repetitive trauma, moisture, psoriasis, fungal infection, thyroid disease and medications that cause photosensitivity.
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Quick Answer
Onycholysis is painless lifting of the nail off its bed, making the separated part look white or yellow. Common causes are repeated trauma or over-manicuring, prolonged wet work, nail psoriasis, fungal infection, thyroid disease and photosensitising drugs. Treatment means removing the cause, keeping the nail short and dry, and treating any infection — the nail reattaches only as it grows out, over 4–6 months for fingernails.
Symptoms
- White, yellow or opaque area where the nail has lifted
- Separation beginning at the free edge
- Usually painless
- Green discolouration if Pseudomonas colonises the space
- Thickening or pitting if psoriasis or fungus is involved
Causes & Risk Factors
- Repetitive trauma, aggressive manicuring, or cleaning under the nail
- Prolonged wet work and detergent exposure
- Nail psoriasis and fungal nail infection
- Thyroid disease (especially hyperthyroidism)
- Photosensitising drugs such as tetracyclines and psoralens
Treatment & Management
- Clipping the nail back to the point of attachment
- Keeping the nail dry; cotton-lined gloves for wet work
- Stopping manicures, gels and cleaning under the nail
- Antifungal or antipsoriatic treatment when indicated
- Topical antiseptic for Pseudomonas green nail
When to See a Doctor
See a doctor if only one nail is affected with dark pigment or bleeding, if the nail fold is inflamed, or if separation is spreading despite protective measures — a nail sample or biopsy may be needed.
Frequently Asked Questions
Will my nail reattach?
The separated portion never reattaches, but a new nail grows attached from the base once the cause is removed. Fingernails take 4–6 months to grow out fully, toenails 12–18 months.
Why has my nail turned green?
Pseudomonas bacteria colonise the damp space under a lifted nail, producing a green pigment. It is not dangerous but needs the nail kept dry and clipped, plus a topical antiseptic.
Medical References
Information on this page is sourced from and verified against reputable medical resources:
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Medical Disclaimer: This information is for educational purposes only and is not intended as medical advice. The content on this page should not be used to diagnose or treat any health problem. Always consult with a qualified healthcare professional for proper medical evaluation, diagnosis, and treatment of your condition.