Final answer:
A yellow green spot on the nail that turns black and begins to emit a bad odor suggests a fungal infection of the nail, known as onychomycosis.
Step-by-step explanation:
The nail condition characterized by a yellow green spot that turns black and begins to smell bad is usually indicative of a fungal infection, commonly known as onychomycosis. Onychomycosis is caused by various types of fungi, including dermatophytes and Candida species, which can lead to the nail becoming yellow, thickened, brittle, and potentially producing a foul odor. If left untreated, the infection can progress to the point where the nail plate separates from the nail bed, causing further discoloration and potentially releasing a bad smell as the infection worsens.
Treatment of fungal nail infections often involves antifungal medications, either topical or oral, but may also require the removal of the affected nail. It’s crucial to maintain good foot hygiene, keep the nails dry and clean, and ensure proper disinfection of nail tools to prevent such infections.