N–O

nails The hardened epidermal layer covering the
top surfaces of the tips of the fingers and toes. Nails
are made of cornified, compacted SKINcells (ker-
atinocytes) that grow from the base of the nail
(matrix or nail-bed root). Though the cells of the
matrix are alive, the cells that make up the nails are
dead. New cell growth from the matrix pushes the
nail outward across the tip of the finger or toe. In
adults the fingernails grow about two tenths inch in

a week. The cells the matrix produces today will

reach the end of the finger in about six months.

Like the skin, the nails provide insights into the

overall health situation of an individual. Certain

changes in the nails signal specific health condi-

tions. Such characteristics include

• banding: stripes of dark or light across the
  width of the nail bed, visible through the nail

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HEALTH IMPLICATIONS OF NAIL CHARACTERISTICS

Nail Characteristic Possible Health Implications
Beau’s lines serious injury or illness that disrupts nail growth

clubbing chronic pulmonary conditions, HEART FAILURE, low blood oxygen
levels

dark band at tops of nails, bottoms of nails normal color age, CANCER, congestive heart failure,DIABETES, CIRRHOSIS,
(Terry’s nails) HYPERTHYROIDISM

koilonychia iron-deficiencyANEMIA

leukonychia arsenic poisoning, mineral deficiency, trauma to the nail matrix

onycholysis thyroid disease, fungal INFECTION, PSORIASIS, adverse DRUGreaction

PETECHIAE(pinpoint hemorrhages) ENDOCARDITIS, THROMBOCYTOPENIA, SYSTEMIC LUPUS ERYTHEMATOSUS(SLE)

stippling psoriasis,ALOPECIA AREATA, injury to the nail

white band at the bottoms of nails, tops of nails normal UREMIA, KIDNEYfailure
color (half-and-half nails)

yellow nail syndrome (yellow-green discoloration consistent chronic pulmonary disorders such as BRONCHITISand EMPHYSEMA,
through all nails) NICOTINEstaining