在一项针对 305,932 例患者的横断面研究中，调整后的晕厥发病率在 0.80 至 0.93/1000 人年之间，从 2000 年到 2005 年，没有发生改变。估计总死亡率也一直保持在 0.28% 左右。 55%-82% 的晕厥患者可以确定病因。 老年晕厥住院患者中，非心血管因素的比例（例如血管迷走神经性或直立性发作）是心血管因素的两倍（例如心律失常或心肌缺血）。
Kearney Regional Medical Center
SW declares that he has no competing interests.
Dr Sanjeev Wasson would like to gratefully acknowledge Dr Sarabjeet Singh and Dr Nishant Kalra, the previous contributors to this topic. SS and NK declare that they have no competing interests.
Assistant Professor of Medicine
Harvard Medical School
The Clinical Decision Unit and Cardiac Emergency Center
Beth Israel Deaconess Medical Center
SG declares that he has no competing interests.
Professor of Medicine
VA Greater Los Angeles Healthcare System
UCLA School of Medicine
DL declares that he has no competing interests.
Heart and Lung Centre
New Cross Hospital
SP has received funds for attending conferences, and fees for speaking and consultation, from Medtronic Inc. SP was also in receipt of funding for research, between 2007 and 2009, from Medtronic Inc. to the University of Manchester. SP was a Guideline Development Group member of the National Institute or Health and Care Excellence (formerly National Institute for Clinical Excellence) guidelines on transient loss of consciousness ('blackouts') management in adults and young people, published in August 2010.
Department of Cardiology
King's College Hospital
NG declares that he has no competing interests.