Illness
Part of speech: noun
Definition: An instance of a disease. A person's perception of having poor health. A state of having bad health
Example sentence: We must bring the issue of mental illness out into the sunlight, out of the shadow, out of the closet, deal with it, treat people, have centers where people can get the necessary help.
Unwellness
Part of speech: noun
Definition: The state or characteristic of being unwell; a feeling of slight to moderate sickliness.