Disease Classification and Terminology

  • A disease is an abnormal condition that affects an organism's structure or function.
  • Diseases can be physical or psychiatric.
  • They can be caused by external factors like pathogens or internal dysfunctions.
  • The four main types of diseases are infectious, deficiency, hereditary, and physiological.
  • Disease, disorder, morbidity, sickness, and illness are often used interchangeably.
  • Disease refers to any condition that impairs normal bodily functioning.
  • Infectious diseases result from the presence of pathogenic microbial agents.
  • Non-infectious diseases include cancer, heart disease, and genetic disorders.
  • Acquired disease occurs after birth, while congenital disease is present at birth.
  • Acute diseases are short-term in nature, while chronic diseases persist over time.
  • Congenital disorders can be genetic or result from vertically transmitted infections.
  • Genetic diseases are caused by genetic mutations, which can be inherited.
  • Iatrogenic diseases are caused by medical intervention.
  • Idiopathic diseases have unknown causes or sources.
  • Incurable diseases cannot be cured but may have manageable symptoms.
  • Primary diseases have a root cause, while secondary diseases are complications.
  • Terminal diseases are expected to result in death.
  • Illness refers to the patient's personal experience of their disease.
  • Some diseases have known causes, while others have associations without clear causality.
  • The study of diseases is called pathology.
  • It includes the study of etiology, or the cause of diseases.
  • Pathology helps understand the mechanisms and effects of diseases.
  • Medical science continues to uncover causes of previously unknown diseases.
  • Some diseases can be managed with medications, even if they are incurable.

Illness, Disorder, and Medical Condition

  • Illness can refer to the experience of feeling unwell or distressed without necessarily having a disease.
  • Symptoms of illness are often a collection of evolved responses by the body to clear infection and promote recovery.
  • A disorder is a functional abnormality or disturbance in the body.
  • Medical disorders can be categorized into mental disorders, physical disorders, genetic disorders, emotional and behavioral disorders, and functional disorders.
  • The term 'disorder' is often considered more value-neutral and less stigmatizing than 'disease' or 'illness.'
  • A medical condition encompasses all diseases, lesions, disorders, or nonpathologic conditions that normally receive medical treatment.
  • In some contexts, the term 'medical condition' specifically excludes mental illnesses.
  • The Diagnostic and Statistical Manual of Mental Disorders (DSM) uses the term 'general medical condition' to refer to all diseases, illnesses, and injuries except for mental disorders.
  • Morbidity refers to a diseased state, disability, or poor health due to any cause.
  • It can refer to the existence of any form of disease or the degree to which a health condition affects a patient.
  • Morbidity rates are used in actuarial professions to determine insurance premiums and predict the likelihood of developing specific diseases.
  • A syndrome is the association of several signs and symptoms that often occur together, regardless of the known cause.
  • Some syndromes have a known cause, while others have multiple possible causes.
  • Syndromes may retain their name even after an underlying cause is found or when there are multiple possible primary causes.
  • Predisease refers to a subclinical or prodromal stage that precedes the development of a disease.
  • Identifying legitimate predisease can lead to preventive measures, but labeling a healthy person with an unfounded notion of predisease can result in overtreatment.
  • Three criteria for predisease include a high risk for progression to disease, actionability for risk reduction, and a benefit that outweighs the harm of interventions taken.

Stages of Disease

  • Incubation period: time between infection and appearance of symptoms
  • Latency period: time between infection and ability to spread the disease
  • Viral latency: dormant phase of some viruses in the body
  • Acute disease: short-lived disease like the common cold
  • Chronic disease: long-lasting disease that can be stable or progressive
  • Clinical disease: stage that produces characteristic signs and symptoms
  • AIDS: clinical disease stage of HIV infection
  • Cure: end of a medical condition or treatment
  • Remission: disappearance of symptoms, possibly temporarily
  • Flare-up: recurrence or onset of more severe symptoms
  • Localized disease: affects only one part of the body
  • Disseminated disease: spread to other parts of the body
  • Systemic disease: affects the entire body
  • Metastatic disease: spread of cancer to other parts of the body
  • Nosology: classification of diseases by cause, pathogenesis, or symptoms

Causes of Disease

  • Pathogens: microorganisms that cause infectious diseases
  • Contagious diseases: transmitted from person to person
  • Non-infectious diseases: not caused by pathogens, often genetic
  • Social determinants of health: social, economic, and environmental factors influencing health
  • Misunderstandings of disease cause: cultural beliefs and myths
  • Airborne diseases: transmitted through the air
  • Foodborne illnesses: caused by contaminated food
  • Infectious diseases: resulting from the infection and growth of pathogens
  • Lifestyle diseases: influenced by factors like physical activity and nutrition
  • Genetic diseases: transmitted from one generation to another

Prevention, Treatments, Epidemiology, and Burdens of Disease

  • Prevention: sanitation, proper nutrition, adequate exercise, vaccinations, obligatory face mask mandates
  • Treatments: medications, surgery, medical devices, self-care, treatment for medical emergencies
  • Epidemiology: study of factors that cause or encourage diseases, identifying risk factors, study design, data collection and analysis, development of statistical models, interaction of diseases in a population
  • Burdens of Disease: disease burden measured by financial cost, mortality, morbidity, years of potential life lost (YPLL), quality-adjusted life year (QALY) and disability-adjusted life year (DALY), heart disease and stroke cause the most loss of life

Disease Mentions


Disease Data Sources

Reference URL
Glossary https://www.alternix.com/blogs/glossary-of-terms/disease
Wikipedia http://en.wikipedia.org/wiki/Disease
Wikidata https://www.wikidata.org/wiki/Q12136
Knowledge Graph https://www.google.com/search?kgmid=/m/027x3