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Basics

• Summary
• Start Here
• Prevention and Risk Factors
• Treatments and Therapies

Learn More

• Related Issues
• Specifics
• Genetics

See, Play and Learn

• Images
• Test Your Knowledge

Research

• Clinical Trials
• Journal Articles

Resources

• Find an Expert

For You

• Children
• Patient Handouts

Summary

Your toenails and fingernails protect the tissues of your toes and fingers. They are made up of layers of a hardened protein called keratin, which is also in your hair and skin. The health of your nails can be a clue to your overall health. Healthy nails are usually smooth and consistent in color. Specific types of nail discoloration and changes in growth rate can be signs of lung, heart, kidney, and liver diseases, as well as diabetes and anemia. White spots and vertical ridges are harmless.

Nail problems that sometimes require treatment include:

• Bacterial and fungal infections
• Ingrown nails
• Tumors
• Warts

Keeping your nails clean, dry, and trimmed can help you avoid some problems. Do not remove the cuticle, which can cause infection.

Start Here

• Fingernails: Do's and Don'ts for Healthy Nails (Mayo Foundation for Medical Education and Research) Also in Spanish

Prevention and Risk Factors

• Healthy Habits: Nail Hygiene (Centers for Disease Control and Prevention)
• Tips for Healthy Nails (American Academy of Dermatology)

Treatments and Therapies

• Tips To Care for an Injured Nail (American Academy of Dermatology)

Related Issues

• Artificial Nails: Dermatologists' Tips for Reducing Nail Damage (American Academy of Dermatology)
• How to Stop Biting Your Nails (American Academy of Dermatology)
• Manicure and Pedicure Safety (American Academy of Dermatology)

Specifics

• Brittle Splitting Nails (Onychoschizia) (American Osteopathic College of Dermatology)
• Funky Fingertips? What Nails Say about Your Health (National Institutes of Health) Also in Spanish
• Green Nail Syndrome (American Osteopathic College of Dermatology)
• Ingrown Toenails (American Academy of Family Physicians) Also in Spanish
• Nail Fungus (Mayo Foundation for Medical Education and Research) Also in Spanish
• Nail Ridges: Cause for Concern? (Mayo Foundation for Medical Education and Research) Also in Spanish
• Onycholysis (American Osteopathic College of Dermatology)
• Paronychia (American Academy of Family Physicians) Also in Spanish
• Subungual Hematoma (American Osteopathic College of Dermatology)
• Thick Toenails (American College of Foot and Ankle Surgeons) Also in Spanish
• Toenail Fungus (Onychomycosis) (American Podiatric Medical Association)
• White Toenails (American College of Foot and Ankle Surgeons) Also in Spanish

Genetics

• Anonychia congenita: MedlinePlus Genetics (National Library of Medicine)
• Nail-patella syndrome: MedlinePlus Genetics (National Library of Medicine)
• Nonsyndromic congenital nail disorder 10: MedlinePlus Genetics (National Library of Medicine)

Images

• Beau Lines (VisualDX)
• Fungal Nail Infection (Onychomycosis) (VisualDX)
• Nail Infection (Paronychia) (VisualDX)
• Nail Lifting (Onycholysis) (VisualDX)
• Nail Splitting (Onychoschizia) (VisualDX)

Test Your Knowledge

• Quiz: Nails (Nemours Foundation)

Clinical Trials

• ClinicalTrials.gov: Nail Diseases (National Institutes of Health)
• ClinicalTrials.gov: Onychomycosis (National Institutes of Health)
• ClinicalTrials.gov: Paronychia (National Institutes of Health)

Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)

• Article: Targeting nail psoriasis: IL-17A inhibitors demonstrate site-specific superiority over IL-23 inhibitor...
• Article: Research and Application of Methods for Improving Nail Permeation: A Review.
• Article: Clinical Characteristics of Nail Unit Melanoma in Türkiye: The Experience of...
• Nail Diseases -- see more articles

Find an Expert

• Find a Dermatologist (American Academy of Dermatology)
• National Institute of Arthritis and Musculoskeletal and Skin Diseases Also in Spanish

Children

• Paronychia (Nail Infection) (For Parents) (Nemours Foundation) Also in Spanish
• Your Nails (Nemours Foundation) Also in Spanish

Patient Handouts

• Aging changes in hair and nails (Medical Encyclopedia) Also in Spanish
• Fungal nail infection (Medical Encyclopedia) Also in Spanish
• Ingrown toenail (Medical Encyclopedia) Also in Spanish
• Ingrown toenail removal - discharge (Medical Encyclopedia) Also in Spanish
• Nail abnormalities (Medical Encyclopedia) Also in Spanish
• Nail injuries (Medical Encyclopedia) Also in Spanish
• Paronychia (Medical Encyclopedia) Also in Spanish
• Splinter hemorrhages (Medical Encyclopedia) Also in Spanish