What can cause nail discoloration?

Nail discoloration can be attributed to a variety of factors, all of which are relevant in this context. Inadequate hygiene can lead to the accumulation of bacteria, fungi, or other contaminants, which may discolor the nails. Excess moisture can also affect the nails; when they remain damp for extended periods, this can create an environment conducive to fungal infections, which in turn can lead to discoloration. Additionally, certain nail products, such as colored polishes or treatments, can stain the nails if they are used improperly or left on for too long. Therefore, considering these three contributing factors, it is accurate to say that all of the options listed can indeed cause nail discoloration.