Fungal nail infection (onychomycosis) on the toe of a 76 year old male patient. Symptoms of this condition include a nail or nails that are thickened, discoloured, brittle and misshapen. Risk factors for the infection include older age, having athlete's foot in the past, walking barefoot in damp areas and diabetes. Keeping nails clean and dry can help prevent this condition. It can be treated with antifungal drugs and medicated nail cream.