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Sep 4, 2023 · Fever, or pyrexia, is the elevation of an individual's core body temperature above a 'set-point' regulated by the body's thermoregulatory center in the hypothalamus. This increase in the body's 'set-point' temperature is often due to a physiological process brought about by infectious causes or non-infectious causes such as inflammation, malignancy, or autoimmune processes. These processes ...
- 2023/09/04
- Overview
- A temperature-sensitive signaling pathway
- The protein that alters temperature reactivity
Researchers claim that fevers are more than just a symptom of illness or infection. They found that elevated body temperature sets in motion a series of mechanisms that regulate our immune system.
When we are healthy, our body temperature tends to gravitate around 37°C (98.6°F).
But when faced with an infection or virus, body temperature often goes up, resulting in a fever.
When someone’s body temperature rises to about 38°C (100.4°F0, doctors classify it as a slight fever. Larger increases in body temperature to around 39.5°C (103.1°F) count as a high fever.
When a person has the flu, for instance, they may experience a mild and uncomfortable fever. This may drive many people to seek natural or over-the-counter remedies to treat it.
However, fevers are not always a bad sign. Mild fevers are a good indication that the immune system is doing its job. But fevers are not just a byproduct of the immune response.
A signaling pathway called Nuclear Factor kappa B (NF-κB) plays an important role in the body’s inflammation response in the context of infection or disease.
NF-κB are proteins that help to regulate gene expression and the production of certain immune cells.
These proteins respond to the presence of viral or bacterial molecules in the system, and that is when they start switching relevant genes related to the immune response on and off at cellular level.
Dysregulated NF-κB activity has been linked with the presence of autoimmune diseases, such as psoriasis, irritable bowel diseases, and rheumatoid arthritis.
The researchers note that NF-κB activity tends to slow down the lower the body temperature. But when the body temperature is elevated over 37°C (98.6°F), it tends to become more intense.
Why does this happen? The answer, they hypothesized, might be found by looking at a protein known as A20, encoded by the gene with the same name.
The researchers involved in the study wondered whether blocking the expression of the A20 gene would affect the way in which NF-κB functioned.
And, sure enough, they found that in the absence of the A20 protein, NF-κB activity no longer reacted to changes in body temperature, and its activity therefore no longer increased in case of a fever.
These findings might also be relevant to the normal fluctuations in temperature that our bodies undergo every day, and how these may affect our response to pathogens.
As Prof. Rand explains, our body clock regulates our internal temperature and determines mild fluctuations — of about 1.15°C at a time — during wakefulness and sleep.
So, he says, “[T]he lower body temperature during sleep might provide a fascinating explanation into how shift work, jet lag, or sleep disorders cause increased inflammatory disease.”
Although many genes whose expression is regulated by NF-κB were not temperature-sensitive, the researchers found that certain genes — which played a key role in the regulation of inflammation and which impacted cell communication — did, in fact, respond differently to different temperatures.
May 7, 2022 · A fever is a temporary rise in body temperature. It's one part of an overall response from the body's immune system. A fever is usually caused by an infection. For most children and adults, a fever may be uncomfortable. But it usually isn't a cause for concern. For infants, however, even a low fever may mean there's a serious infection.
An older term, febricula (a diminutive form of the Latin word for fever), was once used to refer to a low-grade fever lasting only a few days. This term fell out of use in the early 20th century, and the symptoms it referred to are now thought to have been caused mainly by various minor viral respiratory infections .
A fever is a symptom, not an illness. A doctor may wish to carry out tests to identify the cause. If the fever is due to a bacterial infection, they may prescribe an antibiotic .
Apr 3, 2023 · Fever generally can be defined as an early morning temperature higher than 99 degrees Fahrenheit or a temperature higher than 100 degrees Fahrenheit at any time of the day. A part of the brain called the hypothalamus acts as the body's thermostat. When all is well in the body, the hypothalamus is set at the normal body temperature.
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May 31, 2022 · Summary. Fever refers to a body temperature of 100.4 °F (38°C) or more. Fever is a symptom of the body’s reaction to an underlying cause. These causes can include infection, inflammatory diseases, certain medications, blood clots, and cancer, among other factors.