Global InformationInflammation information
 | This article needs more reliable medical references for verification or relies too heavily on primary sources. (March 2021) |  |
| Inflammation | |
|---|---|
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| The cardinal signs of inflammation include: pain, heat, redness, swelling, and loss of function. Some of these indicators can be seen here due to an allergic reaction. | |
| Specialty | Immunology, rheumatology |
| Symptoms | Heat, pain, redness, swelling |
| Complications | Asthma, pneumonia, autoimmune diseases |
| Duration | Acute: few days Chronic: up to many months, or years |
| Causes | Infection, physical injury, autoimmune disorder |
Inflammation (from Latin: inflammatio) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants.[1][2] The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin calor, dolor, rubor, tumor, and functio laesa).
Inflammation is a generic response, and therefore is considered a mechanism of innate immunity, whereas adaptive immunity is specific to each pathogen.[3]
Inflammation is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out damaged cells and tissues, and initiate tissue repair. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. bacteria) and compromise the survival of the organism. However inflammation can also have negative effects.[4] Too much inflammation, in the form of chronic inflammation, is associated with various diseases, such as hay fever, periodontal disease, atherosclerosis, and osteoarthritis.
Inflammation can be classified as acute or chronic. Acute inflammation is the initial response of the body to harmful stimuli, and is achieved by the increased movement of plasma and leukocytes (in particular granulocytes) from the blood into the injured tissues. A series of biochemical events propagates and matures the inflammatory response, involving the local vascular system, the immune system, and various cells in the injured tissue. Prolonged inflammation, known as chronic inflammation, leads to a progressive shift in the type of cells present at the site of inflammation, such as mononuclear cells, and involves simultaneous destruction and healing of the tissue.
Inflammation has also been classified as Type 1 and Type 2 based on the type of cytokines and helper T cells (Th1 and Th2) involved.[5]
The term inflammation is not a synonym for infection. Infection describes the interaction between the action of microbial invasion and the reaction of the body's inflammatory response—the two components are considered together in discussion of infection, and the word is used to imply a microbial invasive cause for the observed inflammatory reaction. Inflammation, on the other hand, describes just the body's immunovascular response, regardless of cause. But, because of the two are often correlated, words ending in the suffix -itis (which means inflammation) are sometimes informally described as referring to infection: for example, the word urethritis strictly means only "urethral inflammation", but clinical health care providers usually discuss urethritis as a urethral infection because urethral microbial invasion is the most common cause of urethritis.
However, the inflammation–infection distinction is crucial in situations in pathology and medical diagnosis that involve inflammation that is not driven by microbial invasion, such as cases of atherosclerosis, trauma, ischemia, and autoimmune diseases (including type III hypersensitivity).
- ^ Ferrero-Miliani L, Nielsen OH, Andersen PS, Girardin SE (February 2007). "Chronic inflammation: importance of NOD2 and NALP3 in interleukin-1beta generation". Clinical and Experimental Immunology. 147 (2): 227–235. doi:10.1111/j.1365-2249.2006.03261.x. PMC 1810472. PMID 17223962.
- ^ Chen L, Deng H, Cui H, Fang J, Zuo Z, Deng J, et al. (January 2018). "Inflammatory responses and inflammation-associated diseases in organs". Oncotarget. 9 (6). Impact Journals, LLC: 7204–7218. doi:10.18632/oncotarget.23208. PMC 5805548. PMID 29467962. S2CID 3571245.
- ^ Abbas AB, Lichtman AH (2009). "Ch.2 Innate Immunity". In Saunders (Elsevier) (ed.). Basic Immunology. Functions and disorders of the immune system (3rd ed.). Saunders/Elsevier. ISBN 978-1-4160-4688-2.
- ^ "Inflammation and Your Health". Cedars-Sinai.
- ^ Berger A (August 2000). "Th1 and Th2 responses: what are they?". BMJ. 321 (7258): 424. doi:10.1136/bmj.321.7258.424. PMC 27457. PMID 10938051. Archived from the original on 12 July 2021. Retrieved 1 July 2021.