What are the main causes of nail discoloration?

Nail discoloration can occur for several reasons, and the most significant causes include trauma, infection, or chemical exposure. Trauma to the nail can cause bleeding underneath the nail plate, leading to a dark coloration. Infections, particularly fungal infections, can result in changes to the color of the nails, often giving them a yellowish or even greenish hue. Chemical exposure, such as from harsh cleaning agents or certain nail products, can also alter the nail’s color, leading to discoloration.

While excessive filing, incorrect nail polish application, and the use of non-professional products may negatively impact the health and appearance of nails, they are not typically recognized as primary causes of discoloration. Excessive filing may cause thinning or damage to the nail but not necessarily change its color. Incorrect application of nail polish can lead to surface issues but doesn't typically impact the underlying nail’s pigmentation. Using non-professional products could potentially harm the nails, but again, it’s not a leading cause of discoloration compared to the more direct impacts of trauma, infections, and chemicals.