2007 年，英国有 2034 例因哮喘的死亡记录。[67]Office for National Statistics. Mortality statistics: deaths registered in 2007. 2008. http://www.statistics.gov.uk (last accessed 14 September 2016).http://www.ons.gov.uk/ons/rel/vsob1/mortality-statistics--deaths-registered-in-england-and-wales--series-dr-/2007/mortality-statistics--deaths-registered--series-dr-.pdf 在美国，每年约有 5000 人死于哮喘，其中大部分是可以通过治疗预防的。[38]National Heart, Lung, and Blood Institute. National Asthma Education and Prevention Program expert panel report 3: guidelines for the diagnosis and management of asthma. July 2007. http://www.nhlbi.nih.gov (last accessed 14 September 2016).http://www.nhlbi.nih.gov/guidelines/asthma/asthgdln.htm 如果能够迅速识别症状并给予治疗，加重的预后良好。
随着时间推移，哮喘控制不佳的患者存在发生长期气道改变的风险，而且这种变化可能会变得不可逆转。
与哮喘相关死亡的危险因素包括：住院前口服皮质类固醇的需求增加、既往曾因急性加重而住院治疗以及就诊时峰流量较低。
几项研究显示，使用吸入性皮质类固醇可降低入院率和死亡率。[68]O'Byrne PM, Barnes PJ, Rodriguez-Roisin R, et al. Low dose inhaled budesonide and formoterol in mild persistent asthma: the OPTIMA randomized trial. Am J Respir Crit Care Med. 2001;164:1392-1397.http://www.ncbi.nlm.nih.gov/pubmed/11704584?tool=bestpractice.com[69]Suissa S, Ernst, P, Benayoun S, et al. Low-dose inhaled corticosteroids and the prevention of death from asthma. N Engl J Med. 2000;343:332-336.http://www.ncbi.nlm.nih.gov/pubmed/10922423?tool=bestpractice.com
