Although these terms are used interchangeably, there is a difference between illness and disease. And this difference is a key concept that student nurses must ingest throughout their education. To understand the difference between illness and disease, we must first define each term and then apply their definitions to nursing and medicine.
What is illness?
An illness refers to the human response to disease. Let’s say a patient has diabetes. What is the human response to having diabetes? Mentally, a newly diagnosed diabetes patient may experience denial. This denial can include refusing to monitor glucose levels or change dietary habits. Physically, a diabetes patient may experience abnormal blood glucose levels resulting in hyper/hypoglycemia. In 1972, Dr Anthony Suchman defined what we know today as the four stages illness:
-Experiencing signs and symptoms
-Assuming the sick role, or validating the sickness
-Seeking medical care
-Assuming dependent role while recovering
What is Disease?
A disease is an alteration of the mental and/or physical structure of the human body or mind. Diseases can have numerous causes: biological (like viruses), chemical (like drugs or heavy metals), genetics, physical agents (like temperature extremes), and alterations in immunity or metabolism (like allergies or hormonal disturbances.) With disease comes specific signs and symptoms that manifest themselves, allowing physicians/medical experts to diagnose their patients.
How can student nurses tell the difference between illness and disease?
In a previous article I wrote here on Associated Content, I advised first semester nursing students to think like a nurse and not a doctor. This mentality will help student nurses understand the difference between illness and disease. As a nurse, you will need to diagnose the human response to your patient’s medical problem. That is why there are specific nursing diagnoses you will learn and familiarize yourself with. A physician can diagnose a patient as being diabetic (disease.) But if that diabetic patient does not monitor his glucose levels or make necessary changes in his diet, the nurse can diagnose him with risk for unstable glucose levels (illness.) Thus, nursing is concerned with illness while medicine (or a physician) is concerned with disease.
Priscilla LeMone and Karen Burke, Medical-Surgical Nursing: Critical Thinking In Client Care, 4th edition, Chapter 2 ‘Health and Illness in the Adult Client’, pp 22-23