What causes ridges in fingernails?

Ridges in fingernails can often be attributed to uneven nail growth. The nail plate is formed by the matrix, the tissue located under the base of the nail, and any disturbances or trauma to this area can lead to variations in nail growth. Factors that can cause uneven growth include physical damage, nutritional deficiencies, or health conditions that affect the nail matrix. As the nail grows out from the matrix, variations in growth can manifest as ridges, offering insight into the nail's development over time.

Choosing genetic factors, infections, or improper nail care may not fully capture the primary cause of ridges. While these factors can contribute to nail appearance, uneven nail growth is specifically linked to the structural formation of the nail itself and its growth over time, making it the most apt choice for explaining the occurrence of ridges.