Illness versus disease

“Illness is not the same as disease. Illness is the human response to disease. It refers to the person’s subjective experience of how they feel but does not assume any underlying pathology. Illness can be either organic or psychological. A person can have a disease but not be ill. For example, a girl with epilepsy has a disease, but if she is not having seizures and the epilepsy is asymptomatic she is not ill. A person with a psychosomatic disorder, on the other hand, is ill but does not necessarily have a disease.”

From “Is it all in Your Head?” by Suzanne O’Sullivan, MD