Considerations
Just like the skin, the fingernails tell a lot about your health.
Beau's lines are depressions across the fingernail. These lines can occur after illness, injury to the nail, and when you are malnourished.
Brittle nails are often a normal result of aging. However, they also may be due to certain diseases and conditions.
Koilonychia is an abnormal shape of the fingernail. The nail has raised ridges and is thin and curved inward. This disorder is associated with iron deficiency anemia.
Leukonychia is white streaks or spots on the nails.
Pitting is the presence of small depressions on the nail surface. Sometimes the nail is also crumbling. The nail can become loose and sometimes falls off.
Ridges are tiny, raised lines that develop across or up and down the nail.
Causes
Injury:
Crushing the base of the nail or the nail bed may cause a permanent deformity.
Chronic picking or rubbing of the skin behind the nail can cause a washboard nail.
Long-term exposure to moisture or nail polish can cause nails to peel and become brittle.
Infection:
Fungus or yeast cause changes in the color, texture, and shape of the nails.
Bacterial infection may cause a change in nail color or painful areas of infection under the nail or in the surrounding skin. Severe infections may cause nail loss.
Viral warts may cause a change in the shape of the nail or ingrown skin under the nail.
Certain infections (especially of the heart valve) may cause red streaks in the nail bed ( splinter hemorrhages).
Diseases:
Disorders that affect the amount of oxygen in the blood (such as abnormal heart anatomy and lung diseases including cancer or infection) may cause clubbing.
Kidney disease can cause a build-up of nitrogen waste products in the blood, which can damage nails.
Thyroid diseases such as hyperthyroidism or hypothyroidism may cause brittle nails or splitting of the nail bed from the nail plate (onycholysis).
Severe illness or surgery may cause horizontal depressions in the nails (Beau's lines).
Psoriasis may cause pitting, splitting of the nail plate from the nail bed, and chronic destruction of the nail plate (nail dystrophy).
Other conditions that can affect the appearance of the nails include systemic amyloidosis, malnutrition, vitamin deficiency, and lichen planus.
Skin cancers near the nail and fingertip can distort the nail. Subungal melanoma is a potentially deadly cancer that will normally appear as a dark streak down the length of the nail.
Darkening of the cuticle associated with a pigmented streak may a sign of an aggressive melanoma.
Certain antibiotics can cause lifting of the nail from the nail bed.
Chemotherapy medicines can affect nail growth.
Normal aging affects the growth and development of the nails.
When to Contact a Medical Professional
Call your health care provider if you have:
A new or widening dark streak in the nail
Blue nails
Clubbed nails
Distorted nails
Horizontal ridges
Pale nails
White lines
White color under the nails
If you have splinter hemorrhages, see the doctor immediately.
What to expect at your health care provider's office
The health care provider will look at your nails and ask questions about your symptoms. Questions may include:
Type
What is the abnormality?
Are the nails an abnormal color?
Are they an abnormal shape?
Has the texture changed?
Has the thickness changed?
Are the nails pitted?
Are the nails detached?
Are there ridged nails?
Does the whole end of the finger look enlarged?
Is there a lack of luster?
Are the nails brittle?
Location
Is it the hands?
Is it the feet?
Is it only on one side?
Are both sides the same?
Is it only one specific nail?
Aggravating factors
Have you had an injury to the nail?
Do you bite your nails?
Do you pick your nails or rub the fingers or toes chronically?
Are the nails frequently moist?
Do you use nail polish?
Other
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.
Prevention
Do not bite, pick, or tear at your nails (in severe cases, some people may need psychological help or encouragement to stop these behaviors).
Keep hangnails clipped.
Wear shoes that don't squeeze the toes together, and always cut the nails straight across along the top.
To prevent brittle nails, keep the nails short and avoid nail polish. Use an emollient (skin softening) cream after washing or bathing.
Using the vitamin biotin and clear nail polish that contains protein can help strengthen your nails.
Alternative Names
Beau's lines; Fingernail abnormalities; Spoon nails; Onycholysis; Leukonychia; Koilonychia; Brittle nails
Update Date: 5/13/2011
Kevin Berman, MD, PhD, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
