头晕是指空间定向错乱的感觉，但不存在运动扭曲感。[1]Bisdorff A, Von Brevern M, Lempert T, et al. Classification of vestibular symptoms: towards an international classification of vestibular disorders. J Vestib Res. 2009;19(1-2):1-13.
https://www.doi.org/10.3233/VES-2009-0343
http://www.ncbi.nlm.nih.gov/pubmed/19893191?tool=bestpractice.com
患者可能使用该术语来表示头晕目眩、平衡失调（平衡障碍）、晕厥先兆或眩晕。这些症状类型显著重叠，患者最常报告感觉失衡或不稳。超过 60％ 的患者会出现不止一种类型的头晕。[2]Kerber KA, Callaghan BC, Telian SA, et al. Dizziness Symptom Type Prevalence and Overlap: A US Nationally Representative Survey. Am J Med. 2017 Dec;130(12):1465;e1-1465;e9.
https://www.amjmed.com/article/S0002-9343(17)30714-3/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/28739195?tool=bestpractice.com
头晕是一种常见症状：一般人群中的患病率为 15％ 到 30％，85 岁以上人群的患病率接近 50％。[3]Karatas M. Central vertigo and dizziness: epidemiology, differential diagnosis, and common causes. Neurologist. 2008 Nov;14(6):355-64.
http://www.ncbi.nlm.nih.gov/pubmed/19008741?tool=bestpractice.com
[2]Kerber KA, Callaghan BC, Telian SA, et al. Dizziness Symptom Type Prevalence and Overlap: A US Nationally Representative Survey. Am J Med. 2017 Dec;130(12):1465;e1-1465;e9.
https://www.amjmed.com/article/S0002-9343(17)30714-3/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/28739195?tool=bestpractice.com
[4]Balatsouras DG, Koukoutsis G, Fassolis A, et al. Benign paroxysmal positional vertigo in the elderly: current insights. Clin Interv Aging. 2018;13:2251-2266.
https://www.doi.org/10.2147/CIA.S144134
http://www.ncbi.nlm.nih.gov/pubmed/30464434?tool=bestpractice.com
约有 5% 的急诊科和未经选择门诊就诊是因为头晕，有高达 8％ 的初级卫生保健就诊是因为头晕。[5]Spiegel R, Kirsch M, Rosin C, et al. Dizziness in the emergency department: an update on diagnosis. Swiss Med Wkly. 2017;147:w14565.
https://www.doi.org/10.4414/smw.2017.14565
http://www.ncbi.nlm.nih.gov/pubmed/29282699?tool=bestpractice.com
[6]Bösner S, Schwarm S, Grevenrath P, et al. Prevalence, aetiologies and prognosis of the symptom dizziness in primary care - a systematic review. BMC Fam Pract. 2018 Feb 20;19(1):33.
https://www.doi.org/10.1186/s12875-017-0695-0
http://www.ncbi.nlm.nih.gov/pubmed/29458336?tool=bestpractice.com
其病因多样，包括前庭、心血管、神经系统和心因性原因。[7]Spiegel R, Kirsch M, Rosin C, et al. Dizziness in the emergency department: an update on diagnosis. Swiss Med Wkly. 2017;147:w14565.
https://www.doi.org/10.4414/smw.2017.14565
http://www.ncbi.nlm.nih.gov/pubmed/29282699?tool=bestpractice.com
采集详细病史（尤其要注意患者症状的发生时机和触发因素），可缩小鉴别诊断的范围，可以通过临床查体和（如果需要）进一步辅助检查来证实鉴别诊断。
