Fungal nail infections are common infections that affect both fingernails and toenails, making them discolored, misshapen, thickened, and more likely to crack or break. This condition affects the toenails more than the fingernails. It is technically known as onychomycosis.
Nails that are infected often have the following characteristics: discolored (the nail becomes yellow, white, green, or brown), thickened in some parts, and fragile or cracked. The condition can be painless unless it becomes severe. Some of those who have this condition also have athlete’s foot.