Overview
Nail lifting (onycholysis) is the spontaneous separation (detachment) of the fingernail or toenail from the nail bed at the end of the nail (distal) and/or on the sides of the nail (lateral). The appearance of nail lifting may resemble a half-moon, or the free edge of the nail may rise up like a hood. Nail lifting creates space under the nail that gathers dirt and debris made of protein in the nails (keratin). As water accumulates under the nail, bacteria and yeast can also cause the area to become infected.
Nail lifting may occur with other skin conditions, such as various forms of eczema (including hand dermatitis), psoriasis, and lichen planus. Nail lifting may also occur with underlying medical problems, including thyroid disease, pregnancy, some forms of infection, and rarely some forms of cancer. Other possible causes are injury to the nails, use of nail cosmetics, and aggressive manicures.
Nail lifting may be caused by some medications, such as chemotherapy and drugs made from vitamin A. Some medications (commonly tetracycline) may interact with sunlight to cause nail lifting.