Wellness is being in a good physical and mental state. It is achieved in many ways including rest, healthy diet, and medicine (if there is a sickness).
The meaning of wellness is : the state of being in good health, especially as an actively pursued goal And wellness can be achieved as is more than being free from illness, it is a dynamic process of change and growth. "...a state of complete physical, mental, and social well-being, and not merely the absence of disease or infirmity." "a conscious, self-directed and evolving process of achieving full potential.