Editing Asthma (section)

===Spirometry===
[[Spirometry]] is recommended to aid in diagnosis and management.<ref name="AAAAIfive">{{cite web |author=((American Academy of Allergy, Asthma, and Immunology)) |author1-link=American Academy of Allergy, Asthma, and Immunology |title=Five things physicians and patients should question |work=Choosing Wisely |publisher=ABIM Foundation |url=http://choosingwisely.org/wp-content/uploads/2012/04/5things_12_factsheet_AAAAI.pdf |access-date=August 14, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20121103151124/http://choosingwisely.org/wp-content/uploads/2012/04/5things_12_factsheet_AAAAI.pdf |archive-date=November 3, 2012 }}</ref><ref name="NIHasthmaguide">{{cite book |title=Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma |year=2007 |publisher=National Heart, Lung, and Blood Institute (US) |url=https://www.ncbi.nlm.nih.gov/books/NBK7232/ |id=07-4051 |via=NCBI}}</ref> It is the single best test for asthma.<!-- <ref name=M38/> --> If the [[FEV1|FEV<sub>1</sub>]] measured by this technique improves more than 12% and increases by at least 200 millilitres following administration of a [[bronchodilator]] such as [[salbutamol]], this is supportive of the diagnosis.<!-- <ref name=M38/> --> It  however may be normal in those with a history of mild asthma, not currently acting up.<ref name=M38/> As [[caffeine]] is a bronchodilator in people with asthma, the use of caffeine before a lung function test may interfere with the results.<ref name="pmid20091514">{{cite journal | vauthors = Welsh EJ, Bara A, Barley E, Cates CJ | title = Caffeine for asthma | journal = The Cochrane Database of Systematic Reviews | issue = 1 | pages = CD001112 | date = January 2010 | volume = 2010 | pmid = 20091514 | doi = 10.1002/14651858.CD001112.pub2 | pmc = 7053252 | url = http://openaccess.sgul.ac.uk/2686/1/CD001112.pdf | veditors = Welsh EJ }}</ref> [[Single-breath diffusing capacity]] can help differentiate asthma from [[COPD]].<ref name=M38/> It is reasonable to perform spirometry every one or two years to follow how well a person's asthma is controlled.<ref name=NHLBI07p58>{{harvnb|NHLBI Guideline|2007|p=58}}</ref>