The Disease is found to come from the Latin โdis-eโ, meaning โnot equal.โ The reason for using this word was because it was not common for the Disease to be equivalent to that of an Illness,
yet Illness and Disease are bewildering, extremely confusing, and close words that may seem exceptionally similar.
Key Takeaways
- Illness refers to an individualโs subjective health experience, while disease represents a medically identified condition or disorder.
- Disease can exist without causing illness and can be present without a specific underlying disease.
- Diagnosis and treatment focus on disease, whereas illness management includes psychological, emotional, and social support.
Illness vs Disease
Illness refers to the subjective experience of being unwell or having a feeling of discomfort or pain, which may or may not be associated with a specific disease or medical condition. The disease is a pathological condition of the body or mind characterized by specific signs and symptoms.

Illness is an inability to function in a healthy way for prolonged periods. This is due to the body being unable to overcome infection or another health issue.
In modern times, it has become harder and harder for people to stay healthy, leading to Illnesses such as Crohnโs disease and asthma being on the rise.
The Disease is an abnormal condition of a structure or function that impairs normal activity. To differentiate Diseases, physicians use the term pathophysiology.
Diseases can have a wide range of causes, from genetics to environmental exposure. For instance, one person may have a genetic disorder that causes haemophilia, while another may get it through an insect bite.
Comparison Table
Parameters of Comparison | Illness | Disease |
---|---|---|
Definition | Illness is an inability to function in a healthy way for prolonged periods. | The Disease is a condition or disorder of any body structure and function. |
Manifestation | It does not cause any specific manifestation of a known cause. | It causes specific manifestation and has a known cause. |
Remedy | It can be cured by an individual on their own. | Requires professional care and medicaments. |
Death-Dealing | The Illness is not death-dealing. | The Disease can be death-dealing. |
Illustration | Bacterial infection, depression, inflammation, stress, and anxiety. | Hepatitis A, Salmonella poisoning, Lyme disease, cancer, and AIDS. |
What is Illness?
As Illness is a symptom of poor health, several factors can lead to one getting sick.
Some of these factors include following an infection or allergen, and the body can often heal itself by fighting off the lingering virus or bacteria and reducing inflammation that comes with the immune systemโs response,
however, in some instances, the body is unable to beat off whatever is causing the issues, and sickness sets in.
Emotionally and mentally, the bodyโs immune system is often depleted during illnesses as it focuses on fighting off whatever is causing the symptoms.
As a result of this, people who have an Illness often find that they are more anxious or depressed than usual, moreover, It remains difficult to predict how long someone will suffer from any given Illness, especially once symptoms have set in.
Illnesses are more treated on your own, often aided by over-the-counter medications, while many Illnesses are not dangerous, however, Illness can be fatal at times.
Many Illnesses can lead to other problems, many of which are unrelated to the original infection or allergen.
For example, sickle cell anaemia can cause inflammation in the blood, leading to infection in other parts of the body and frequent infections during pregnancy.

What is Disease?
The word โDiseaseโ is a medical term that refers to an abnormal condition or state of the body that arises from a specific, determinate cause,
moreover, when the onset of the disease is sudden and marked by acute symptoms, it is termed acute.
When the onset of the disease is gradual and marked by symptoms that persist over an extended period, it is termed chronic.
Acute disease may become chronic if the initial cause remains untreated or unfought or if a new cause develops within the body.
A Disease is a specific medical condition or disorder that causes specific symptoms and has a known cause. It can affect people in defined ways ranging from mild to life-threatening.
Although there are several Diseases, the most common health conditions can be divided into three main categories infectious Diseases, Metabolic Diseases, and neoplastic Diseases.
Diseases fall into different categories depending on their symptoms, the location of the body affected, as well as how they cause health problems, where it is believed that diseases are caused by agents termed pathogens.
Some major Diseases are cancer, AIDS, diabetes, malaria, hepatitis A, Salmonella poisoning, and Lyme disease. These Diseases all affect people in different ways and to varying degrees.

Main Differences Betweenย Illness and Disease
- Illness is an inability to function in a healthy way for prolonged periods of time, whereas, Disease is a condition or disorder of any body structure and function.
- Illness does not cause any specific manifestation of a known cause, whereas, Disease causes a specific manifestation and has a known cause.
- Illness can be cured by an individual on their own, whereas, Disease requires professional care and medicament.
- The Illness is not death-dealing, whereas, Disease can be death-dealing.
- The Illness illustration includes bacterial infection, depression, inflammation, stress, and anxiety, whereas, the Disease illustration includes hepatitis A, Salmonella poisoning, Lyme disease, cancer, and AIDS.

- https://psycnet.apa.org/record/2001-05666-016
- https://www.tandfonline.com/doi/abs/10.1080/08870440008400303
- https://www.degruyter.com/document/doi/10.36019/9780813549736-002/html
Piyush Yadav has spent the past 25 years working as a physicist in the local community. He is a physicist passionate about making science more accessible to our readers. He holds a BSc in Natural Sciences and Post Graduate Diploma in Environmental Science. You can read more about him on his bio page.