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Although transient loss of consciousness (TLOC) is a common problem, hospital care for patients with TLOC is characterised by high rates of no diagnosis and misdiagnosis, accompanied by unnecessary hospital admissions and tests. We attribute these problems to increasing specialisation as well as to a blind spot for vasovagal syncope, a condition not claimed by any specialty. We suggest that all doctors seeing patients with TLOC, both in primary and secondary care, should be familiar with the presentations of the relatively harmless vasovagal syncope and the alarm symptoms of potentially life-threatening cardiac syncope. In this article we present some practical pointers to recognise these conditions and answer some frequently-asked questions regarding the diagnosis and treatment of TLOC.

Patients with transient loss of consciousness are often seen by a variety of specialists. Even if typical signs occur, it can be difficult to identify specific causes. We discuss two patients with complex presentations. The first patient was diagnosed with sleep syncope, a relatively unknown type of reflex syncope. The prodromal symptoms of discomfort and the subsequent loss of consciousness occurred while the patient was in bed or got up to go to the toilet due to abdominal symptoms. The onset in supine position was misleading, since this is a well-known alarm symptom of a possible cardiac cause. The second patient had vasovagal syncope followed by a psychogenic pseudosyncope. This resulted in frequent loss of consciousness of long duration with typical and atypical triggers and uncommon syncopal signs, including eye closure. These conflicting symptoms can be a pitfall and clinical expertise is required to identify the type of syncope.

Two healthy children, a 10-year-old boy and a 13-year-old girl, both presented with a history of collapse. The boy had had multiple episodes of syncope over a 7-year period. He was diagnosed with reflex syncope on the basis of case history and diagnostic tests. The girl collapsed at school while resting. She was diagnosed with long QT syndrome and was treated with beta-blockers. After DNA-testing both her mother (who had, in retrospect, been wrongly diagnosed with epilepsy), and her brother were also diagnosed with long QT syndrome. Syncope is a common complaint in children and adolescents. In most cases the cause is a benign reflex syncope, but potentially life threatening syncope caused by rare cardiac conditions does occur and needs to be recognized in both the patient and their family members (who may be asymptomatic). Benign reflex syncope and cardiac syncope can be distinguished by performing a thorough medical and family history, physical examination and ECG.

A 29-year-old medical student suffered from vasovagal syncope triggered by blood and blood-related procedures, such as injections and injuries. Fainting was preceded by prodromal symptoms like light-headedness and altered vision. The patient consulted the Syncope Unit at the Academic Medical Centre, Amsterdam, the Netherlands, and received instructions on how to apply counterpressure manoeuvres. He was also successfully treated with psychological deconditioning, which consisted of desensitisation through exposure in vivo and cognitive behavioural therapy. Emotionally triggered vasovagal syncope is predominantly seen in young people and can lead to serious complications. It can be treated with simple interventions like drinking water and performing counterpressure manoeuvres. Psychological deconditioning is an effective additional therapy.