Nail abnormalities

Alternative names
Beau’s lines; Fingernail abnormalities; Spoon nails; Onycholysis; Leukonychia; Koilonychia

Nail abnormalities refer to abnormal color, shape, texture, or thickness of the fingernails or toenails.

Just like the skin, the fingernails are a telling reflection of a person’s state of health.

Pitting (the presence of small depressions on the nail surface) is often accompanied with crumbling of the nail. Detachment of the nail can also occur. (The nail becomes loose and sometimes even comes off.)

Ridges (linear elevations) can develop along the nail occurring in a “lengthwise” or “crosswise” direction.

Beau’s lines are linear depressions that occur “crosswise” (transverse) in the fingernail. They can occur after illness, trauma to the nail, and with malnutrition.

Leukonychia describes white streaks or spots on the nails.

Koilonychia is an abnormal shape of the fingernail where the nail has raised ridges and is thin and concave. This disorder is associated with iron deficiency anemia.

Common Causes

  • A crush injury to base of the nail or the nail bed may produce a permanent deformity  
  • Nail biting can be a sign of anxiety, chronic tension or uncontrollable compulsion  
  • Chronic picking or rubbing of the skin behind the visible portion of the nail can produce a washboard nail  
  • Chronic exposure to moisture or to nail polish can produce brittle nails with peeling of the edge of the nail


  • Fungus or yeast produce changes in the color, texture, and shape of the nails  
  • Bacterial infection may cause a change in color (green nails with Pseudomonas) or painful pockets of infection under the nail or in skin surrounding the nail - severe infections can cause loss of the nail plate  
  • Viral warts may cause a change in the shape of the nail or ingrown skin under the nail

Internal diseases

  • Disorders that affect the amount of oxygen in the blood (such as abnormal heart anatomy and lung diseases including cancer or infection) may produce “clubbing” of the nail, which looks like the back of a teaspoon  
  • Kidney disease that causes a build-up of nitrogen waste products in the blood  
  • Liver disease including chronic liver failure  
  • Thyroid diseases including hyperthyroidism or hypothyroidism may produce brittle nails or splitting of the nail bed from the nail plate (onycholysis)  
  • Infection (especially of the heart valve) may produce splinter hemorrhages (red streaks in the nail bed)  
  • Systemic amyloidosis  
  • Severe illness or surgery may produce horizontal depressions in the nails (Beau’s lines)  
  • Vitamin deficiency can cause a loss of luster or brittle nails  
  • Malnutrition of any sort can affect the appearance of the nails

Skin diseases

  • Psoriasis may produce pitting, splitting of nail plate from nail bed (onycholysis), and chronic destruction of the nail plate (nail dystrophy)  
  • Lichen planus

Heavy metal ingestion

  • Arsenic poisoning may produce white lines and horizontal ridges  
  • Silver intake can produce a blue nail

Home Care
For nail abnormalities due to nail biting, picking, and tearing, stop these behaviors. Get psychological help (in extreme cases) or encouragement to stop as needed. Keep hangnails clipped.

For nail abnormalities due to ingrown toenails, wear shoes that don’t squeeze the toes together, and always cut the nails straight across along the top.

For pale nails, clubbed nails, blue nails, distorted nails, white lines and horizontal ridges, or white hue under the nails, consult your health care provider to determine the proper way to treat the underlying cause of the problem.

For splinter hemorrhages, see the doctor immediately!

For brittle nails, keep the nails short and avoid nail polish. Use an emollient (skin softening) cream after washing or bathing.

Call your health care provider if
If nail abnormalities are unexplained, associated with other symptoms, or persist, call your health care provider.

What to expect at your health care provider’s office
The medical history will be obtained, and a physical examination performed.

Medical history questions documenting your symptom in detail may include:

  • Type       o What is the abnormality?       o Are the nails an abnormal color?           + What color are they?           + Are there red lines running the length of the nail (splinter hemorrhage)?       o Are they an abnormal shape?       o Has the texture changed?       o Has the thickness changed?       o Are the nails pitted?       o Are the nails detached?       o Are there ridged nails?           + Which direction does the ridging go?       o Does the whole end of the finger look enlarged?       o Is there a lack of luster?       o Are the nails brittle?  
  • Location       o Is it the hands?       o Is it the feet?       o Is it only on one side?       o Are both sides the same?       o Is it only one specific nail?  
  • Aggravating factors       o Have you had an injury to the nail?       o Do you bite your nails?       o Do you pick your nails or rub the fingers or toes chronically?       o Are the nails frequently moist?       o Do you use nail polish?  
  • Other       o What other symptoms are also present?

Diagnostic tests will depend on what other symptoms, if any, exist. These may include X-rays, blood tests, or examination of parts of the nail in the laboratory.

Johns Hopkins patient information

Last revised: December 6, 2012
by Dave R. Roger, M.D.

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.