Yellowing, thickened and brittle, crumbling nails may be a sign of toenail fungus (onychomycosis). Nail fungus tends to start mildly, yellowing the leading edge or a corner of the toenail. No pain or discomfort is present at the onset. However, as time goes on, it progresses, leading to damage throughout the nail that deforms its overall shape, size, and appearance. Changes to the nail surface can include ridges, pits, and discoloration. As a result of the nail’s thicker profile, the nail bed can become much more tender due to the increased pressure from footwear. The ragged edges of the brittle nail can also get caught on sheets, clothing, and socks, causing discomfort.
Most cases start with a single affected toenail, but the fungus causing the infection can easily spread to other toes as well, even spreading the skin in the form of athlete’s foot. The same types of fungi can infect fingernails and toenails. However, fungi thrive in moist, dark environments, so the foot can be an ideal host. Most people wear shoes all day, where sweat and warmth provide the right conditions for infection.
While there are a number of available treatments for nail fungus, the safest and most effective is laser treatment, which has been proven to be effective in over 80% of patients for sustaining clear nails.