reactivity
noun
re·ac·tiv·i·ty
(ˌ)rē-ˌak-ˈti-və-tē 
: the quality or state of being reactive
emotional reactivity
chemical reactivity
If the brain, responding to psychological stress, stimulates the release of cortisol and cortisol suppresses the reactivity of the immune system, then a dormant viral infection may well flare up, or a new one catch hold.—
Matt Ridley
Matt RidleyAbnormal reactivity to light and abnormal pupillary size may be important clues to the presence of cranial injury in the setting of head trauma.—Bradford J. Shingleton
Bradford J. ShingletonExamples of reactivity in a Sentence
Recent Examples on the Web
Diets that protect the immune system can benefit everyone, especially those with a disease rooted in immune reactivity, such as allergic asthma.
—Daniel More, Verywell Health, 25 Mar. 2025
Ultimately, to address the issues of episodic care, reactivity, generalized treatment, and siloed approach, the healthcare system of the future must be continuous, proactive, personalized, and integrative.
—Kyle J. Russell, USA TODAY, 6 Mar. 2025
Previous studies have suggested that REM sleep — the stage associated with vivid dreaming — plays a key role in reducing the brain's emotional reactivity the following day by engaging the prefrontal cortex.
—Jenny Lehmann, Discover Magazine, 21 Feb. 2025
The pup named Relic arrived at the East Bay SPCA in Oakland, California with recognizable signs of shelter stress, including reactivity to humans and animals, according to the shelter.
—Saman Shafiq, USA TODAY, 19 Feb. 2025
See All Example Sentences for reactivity
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Daniel More, Verywell Health, 25 Mar. 2025
Ultimately, to address the issues of episodic care, reactivity, generalized treatment, and siloed approach, the healthcare system of the future must be continuous, proactive, personalized, and integrative.
—Kyle J. Russell, USA TODAY, 6 Mar. 2025
Previous studies have suggested that REM sleep — the stage associated with vivid dreaming — plays a key role in reducing the brain's emotional reactivity the following day by engaging the prefrontal cortex.
—Jenny Lehmann, Discover Magazine, 21 Feb. 2025
The pup named Relic arrived at the East Bay SPCA in Oakland, California with recognizable signs of shelter stress, including reactivity to humans and animals, according to the shelter.
—Saman Shafiq, USA TODAY, 19 Feb. 2025
See All Example Sentences for reactivity
Cite this Entry
“Reactivity.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/reactivity. Accessed 7 Apr. 2025.
Copy CitationMedical Definition
reactivity
noun
re·ac·tiv·i·ty
(ˌ)rē-ˌak-ˈtiv-ət-ē
plural reactivities
: the quality or state of being reactive
skin reactivity
emotional reactivity
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