Toenail fungus, or onychomycosis, manifests as changes in the appearance of the toenails, often starting with discoloration, such as yellow, brown, or white spots. As the infection progresses, the toenails may become thickened, brittle, and crumbly, and they may start to lift from the nail bed. The affected nails can also become distorted in shape, which can make wearing shoes uncomfortable and may affect the overall appearance of the feet.

Patients with toenail fungus might experience associated symptoms such as itching, a foul odor, or pain in the affected toenail, especially if the infection is severe. The condition can lead to secondary infections and complications if left untreated, as the compromised nails may allow bacteria to enter the underlying skin. This can cause further discomfort and potentially more serious foot health issues. Treatment typically involves topical or oral antifungal medications, and maintaining good foot hygiene is crucial to managing and preventing the recurrence of toenail fungus.