Illness (sometimes referred to as ill-health or ail) can be defined as a state of poor health. Introduction The mode of being healthy includes, as defined by the World Health Organization, " [...] a state of complete physical, mental and social well-being and not merely the absence of disease or " (WHO, 1946). When these conditions are not fulfilled, then one can be considered to have an illness or be ill. Medication and the science of pharmacology is used to cure or reduce symptoms of an illnes… (More on Illness)