What causes toenails to go bad?

Toenails can deteriorate due to various factors, including fungal infections, trauma or injury, and poor hygiene. Fungal infections can lead to discoloration, thickening, and brittleness. Additionally, underlying health conditions like Diabetes or circulatory issues may contribute to toenail problems. Insufficient nutrition and improper footwear can also exacerbate issues, leading to painful or unsightly toenails.