In the Merriam Webster Dictionary the Definition of ILLNESS is mentioned as under:
1. obsolete. a : wickedness b : unpleasantness 2 . a : an unhealthy condition of body or mind
b : sickness
In the Merriam Webster Learner Dictionary the word illness is defined as follows:
1 [noncount] : a condition of being unhealthy in your body or mind
2 [count]: a specific condition that prevents your body or mind from working normally: a sickness or disease
According to the Merriam Webster Medical Dictionary the Definition of ILLNESS is given as under:
an unhealthy condition of body or mind : sickness
Illness (sometimes referred to as ill-health or ailment) is a state of poor health. Illness is sometimes considered another word for disease. Others maintain that fine distinctions exist. Some have described illness as the subjective perception by a patient of an objectively defined disease.
In the Western World, people usually do not make a distinction between illness and disease. These two terms seem to mean essentially the same thing and are often used interchangeably. However, it is important to define illness and disease differently when considering some non-western cultural traditions. Disease is an objectively measurable pathological condition of the body. Tooth decay, measles, or a broken bone is examples. In contrast, illness is a feeling of not being normal and healthy. Illness may, in fact, be due to a disease. However, it may also be due to a feeling of psychological or spiritual imbalance. By definition, perceptions of illness are highly culture related while disease usually is not. It is important for health professionals who treat people from other cultures to understand what their patients believe can cause them to be ill and what kind of curing methods they consider effective as well as acceptable. Understanding a culture’s perception of illness is also useful in discovering major aspects of their world view.
The mode of being healthy includes, as defined by the World Health Organization, “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity”. When these conditions are not fulfilled, then one can be considered to have an illness or be ill. Medication and the science of pharmacology are used to cure or reduce symptoms of an illness or medical conditions. Developmental disability is a term used to describe severe, life-long disabilities attributable to mental or physical impairments.
Physical
Conditions of the body or mind that cause pain, dysfunction, or distress to the person afflicted or those in contact with the person can be deemed an illness. Sometimes the term is used broadly to include injuries, disabilities, syndromes, infections, symptoms, deviant behaviors, and atypical variations of structure and function, while in other contexts these may be considered distinguishable categories. A pathogen or infectious agent is a biological agent that causes disease or illness to its host. A passenger virus is a virus that simply hitchhikes in the body of a person or infects the body without causing symptoms, illness or disease. Forborne illness or food poisoning is any illness resulting from the consumption of food contaminated with pathogenic bacteria, toxins, viruses, and parasites.
Adaptive response
According to evolutionary medicine, much illness is not directly caused by an infection or body dysfunction but is instead a response created by the body. Fever, for example, is not caused directly by bacteria or viruses but by the body raising its normal human body temperature, which some people believe inhibits the growth of the infectious organism. Evolutionary medicine calls this set of responses sickness behavior. These include such illness defining health changes as lethargy, depression, anorexia, sleepiness, hyperalgesia, and the inability to concentrate. These together with fever are caused by the brain through its top down control upon the body. They are, therefore, not necessary, and often do not accompany an infection (such as the lack of fever during malnutrition or late pregnancy) when they have a cost that outweighs their benefit. In humans, an important factor is beliefs that influence whether the health management system in the brain that evaluates costs and benefits deploys them or not. The health management system, when it factors in false information, has been suggested to underlie the placebo reduction of illness
Mental
Mental illness (or Emotional disability, Cognitive dysfunction) is a broad generic label for a category of illnesses that may include affective or emotional instability, behavioral dysregulation, and/or cognitive dysfunction or impairment. Specific illnesses known as mental illnesses include major depression, generalized anxiety disorder, schizophrenia, and attention deficit hyperactivity disorder, to name a few. Mental illness can be of biological (e.g., anatomical, chemical, or genetic) or psychological (e.g., trauma or conflict) origin. It can impact one’s ability to work or go to school and contribute to problems in relationships. Other generic names for mental illness include “mental disorder”, “psychiatric disorder”, “psychological disorder”, “abnormal psychology”, “emotional disability”, “emotional problems”, or “behavior problem”. The term insanity is used technically as a legal term. Brain damage may result in impairment of mental function.
Study of illness
Epidemiology is the scientific study of factors affecting the health and illness of individuals and populations, and serves as the foundation and logic of interventions made in the interest of public health and preventive medicine.
Behavioral medicine is an interdisciplinary field of medicine concerned with the development and integration of psychosocial, behavioral and biomedical knowledge relevant to health and illness. Clinical Global Impression of scale to assess treatment response in patients with mental disorders. It’s “Improvement scale” requires the clinician to rate how much the patient’s illness has improved or worsened relative to a baseline state. Mental confusion and decreased alertness may indicate that a chronic illness has gotten worse.
