Service
Syncope & blackouts
Syncope — a transient loss of consciousness — is common and usually has a benign cause. A careful, structured assessment is important to identify the minority of cases due to a heart rhythm or structural problem.
Assessment
Assessment begins with a detailed account of the episodes, including any warning symptoms and the circumstances. This is combined with an ECG, echocardiography, and rhythm monitoring appropriate to how often events occur. Further tests, such as tilt testing or exercise testing, are used selectively.
Treatment
Management is directed at the cause — from advice and simple measures for the common reflex faints, through to specific treatment, which may include a pacemaker, where a significant rhythm problem is identified.
When to seek urgent help
Blackouts during exertion, those without warning, or those associated with injury warrant prompt assessment. If you have chest pain or breathlessness with a blackout, call 999.
Common questions
What causes blackouts?
Most blackouts are due to a temporary drop in blood flow to the brain — often a simple faint. A minority are caused by heart rhythm or structural problems, which is why a structured assessment matters.
What tests might I need?
Assessment commonly includes an ECG, an echocardiogram, and ambulatory or longer-term rhythm monitoring. Additional tests such as a tilt test or exercise testing may be used depending on the picture.
Can I still drive?
Driving rules after blackouts depend on the cause and the licence type, and are set by the DVLA. We will advise you on the relevant guidance as part of your assessment.
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Read moreLast reviewed: June 2026. Reviewed by Dr Iain Sim.