Reviewer Info: Michael Lehrer, MD, Department of Dermatology, University of Pennsylvania Medical Center, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.; ADAM Health Illustrated Encyclopedia, 04/17/2009
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.
Common 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.