Beau’s lines are deep grooved lines that run from side to side on the fingernail. They may look like indentations or ridges in the nail plate. This condition of the nail was named by a French physician, Joseph Honoré Simon Beau (1806–1865), who first described it in 1846.

Beau’s Lines are horizontal, going across the nail, and should not be confused with vertical ridges going from the bottom (cuticle) of the nail out to the fingertip. These vertical lines are usually a natural consequence of aging and are harmless. Beau’s Lines should also be distinguished from Muehrcke's lines of the fingernails. While Beau’s Lines are actual ridges and indentations in the nail plate, Muehrcke lines are areas of hypopigmentation without palpable ridges.

There are several reasons that humans get Beau’s Lines . It is believed that there is a temporary cessation of cell division in the nail matrix. This may be caused by an infection or problem in the nail fold, where the nail begins to form, or it may be caused by an injury to that area. Some other reasons for these lines include trauma, coronary occlusion, hypocalcaemia, skin disease, and may be a sign of systemic disease. It may also be caused by an illness of the body, such as diabetes, psoriasis or malnutrition.

This article is copied and/or modified from an article on Wikipedia® - the free encyclopedia created and edited by online user community. Although the vast majority of the Wikipedia® encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.