Which term refers to an "ingrown nail"?

The term "onychocryptosis" specifically refers to an ingrown nail, which occurs when the edge of a nail grows into the surrounding skin, often leading to pain, redness, and swelling. This condition most commonly affects the toenails, but can occur with fingernails as well. The name derives from Greek roots where "onycho" means nail, and "cryptosis" means hidden or buried, which accurately reflects the nature of the problem—where part of the nail is essentially embedded in the flesh.

In contrast, "onychophagy" pertains to the habit of nail-biting, an issue associated with cosmetic and behavioral concern rather than a medical condition like an ingrown nail. "Onyx" is a term for a specific type of nail or can refer to a polished form of a mineral; it does not refer to any condition of the nail. "Eponychium" denotes the cuticle, which is the layer of skin at the base of the nail, not related to the condition of an ingrown nail but more to the anatomy surrounding it. Understanding these distinctions is crucial for recognizing the various terms used in nail health and conditions.