How can I tell if my finch is sick?

A healthy finch has smooth, clean, and well-groomed feathers. If your finch looks fluffed up all the time, it might be sick. Birds fluff their feathers to stay warm when they feel weak or cold. If the feathers look dirty, matted, or dull, it’s a sign of illness. Bald spots or excessive feather loss can also mean stress, mites, or malnutrition.