There is a difference that must be understood between a disease and an illness. A disease is a pathology which a doctor diagnoses from the problem that the patient presents with. An illness is the personal experience of the disease. This takes into account the entire person including their attitudes, feelings, thoughts, and values that surround the disease. This reflects and often defines the disease.
Those doctors that are trained and see themselves as teachers and not just treaters will spend time in a participative role asking questions and helping their patients understand the difference between these two domains. In a busy disease care clinic unfortunately this will never happen. Knowing this difference is enlightening to the patient. It is essential for the growth of the patient and will ease the effects of disease itself.