Editing Pneumonia (section)

===Diagnosis in adults===
In general, in adults, investigations are not needed in mild cases.<ref name=BTS09/> There is a very low risk of pneumonia if all [[vital sign]]s and [[chest auscultation|auscultation]] are normal.<ref>{{cite journal | vauthors = Saldías F, Méndez JI, Ramírez D, Díaz O | title = [Predictive value of history and physical examination for the diagnosis of community-acquired pneumonia in adults: a literature review] | journal = Revista Médica de Chile | volume = 135 | issue = 4 | pages = 517–28 | date = April 2007 | pmid = 17554463 | doi = 10.4067/s0034-98872007000400016 | doi-access = free }}</ref> [[C-reactive protein]] (CRP) may help support the diagnosis.<ref>{{cite journal | vauthors = Ebell MH, Bentivegna M, Cai X, Hulme C, Kearney M | title = Accuracy of Biomarkers for the Diagnosis of Adult Community-acquired Pneumonia: A Meta-analysis | journal = Academic Emergency Medicine | volume = 27 | issue = 3 | pages = 195–206 | date = March 2020 | pmid = 32100377 | doi = 10.1111/acem.13889 | s2cid = 211523779 | doi-access = free }}</ref> For those with CRP less than 20&nbsp;mg/L without convincing evidence of pneumonia, antibiotics are not recommended.<ref name="Elena 2015"/>

[[Procalcitonin]] may help determine the cause and support decisions about who should receive antibiotics.<ref name="pmid29037960">{{cite journal | vauthors = Schuetz P, Wirz Y, Sager R, Christ-Crain M, Stolz D, Tamm M, Bouadma L, Luyt CE, Wolff M, Chastre J, Tubach F, Kristoffersen KB, Burkhardt O, Welte T, Schroeder S, Nobre V, Wei L, Bucher HC, Annane D, Reinhart K, Falsey AR, Branche A, Damas P, Nijsten M, de Lange DW, Deliberato RO, Oliveira CF, Maravić-Stojković V, Verduri A, Beghé B, Cao B, Shehabi Y, Jensen JS, Corti C, van Oers JA, Beishuizen A, Girbes AR, de Jong E, Briel M, Mueller B | title = Effect of procalcitonin-guided antibiotic treatment on mortality in acute respiratory infections: a patient level meta-analysis | journal = The Lancet. Infectious Diseases | volume = 18 | issue = 1 | pages = 95–107 | date = January 2018 | pmid = 29037960 | doi = 10.1016/S1473-3099(17)30592-3 | doi-access = free | hdl = 1843/42632 | hdl-access = free }}</ref> Antibiotics are encouraged if the procalcitonin level reaches 0.25 μg/L, strongly encouraged if it reaches 0.5 μg/L, and strongly discouraged if the level is below 0.10 μg/L.<ref name="Elena 2015"/> In people requiring hospitalization, [[pulse oximetry]], [[chest radiography]] and [[blood test]]s – including a [[complete blood count]], [[serum electrolytes]], C-reactive protein level, and possibly [[liver function tests]] – are recommended.<ref name=BTS09/>

The diagnosis of [[influenza-like illness]] can be made based on the signs and symptoms; however, confirmation of an influenza infection requires testing.<ref name=ILI05>{{cite journal | vauthors = Call SA, Vollenweider MA, Hornung CA, Simel DL, McKinney WP | title = Does this patient have influenza? | journal = JAMA | volume = 293 | issue = 8 | pages = 987–97 | date = February 2005 | pmid = 15728170 | doi = 10.1001/jama.293.8.987 }}</ref> Thus, treatment is frequently based on the presence of influenza in the community or a [[Rapid influenza diagnostic test|rapid influenza test]].<ref name=ILI05/>

Adults 65 years old or older, as well as cigarette smokers and people with ongoing medical conditions are at increased risk for pneumonia.<ref>{{cite web |date=30 September 2022 |title=Risk Factors for Pneumonia|url=https://www.cdc.gov/pneumonia/riskfactors.html |access-date=16 January 2023 |website=CDC |language=en-us}}</ref>