Fill in the box with one of the following words: bacterial, fungal, parasitic, protozoan, viral. Sergio observes thickening and discoloration of the nail of the index finger. His doctor diagnosed Sergio with a nail infection. Sergio is most likely suffering from a/an
infection.

fungal

Explanation:

A "fungal infection" in the nails is called "onychomycosis" or "tinea unguium." A person can directly get a fungal infection from others or from the surroundings he's living in. It causes several symptoms such as the thickening of nails due to inflammation. It also causes "discoloration" (whitish, yellowish, yellow-brown, etc.), which is due to the fungi's having already penetrated deep into the nail bed. Sometimes, the nail also has an odor coming from it and it also looks distorted.

wellness is the state of being in good health, especially as an actively pursued goal.