"Disease" and "illness" are two commonly used words that people often use interchangeably. But when talking about medical problems they are not synonymous.
Don't be hard on yourself if you don't know the differences. Even Merriam-Webster's Collegiate Dictionary (Eleventh Edition) doesn't distinguish them. Medical clinicians do:
- "Disease" refers to an abnormality or malfunctioning of an organism that impairs bodily or psychological functioning and is associated with various signs and symptoms.
- "Illness" refers to the psychosocial experience and meaning of perceived disease.
Put another way, disease affects the body, and illness affects the person with disease.
You can have a disease without having an illness. For example, people with hypertension (a disease) can look, feel and be perfectly healthy (without illness) because their blood pressure is well-controlled on medications that are well tolerated.
Conversely, people can go from doctor to doctor with symptoms they believe stem from some dread disease (they are ill), yet careful evaluations support the conclusion they are healthy (have no disease).
Oftentimes people have a disease that is causing illness. In 1990, I was found to have a disease -- lymphoma. Both the disease and its treatments made me ill. My illness involved changes in all spheres of my life, because my illness -- cancer -- included esophagitis (inflammation of the esophagus), ischemic neuropathy (pain from nerve that was injured when compressed by tumor), insomnia, grief, fear of death, loss of my practice and a spiritual journey.
In my next posts, I'll discuss why the distinction is important to Healthy Survivors and is vital to any discussions about healthcare reform.