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This summary is in the process of being updated. In the meantime, please refer to the most up-to-date guideline on the NICE website

Initial assessment and diagnosis

  • See algorithm below

Advice to give when a person presents with transient loss of consciousness (TLoC)

  • Driving
    • give advice about eligibility to drive. Please refer to the DVLA for further information
  • Health and safety at work
    • advise people of the implications of their episode for health and safety at work and any action they must take to ensure the safety of themselves and other people

Red flags

  • Refer within 24 hours for specialist cardiovascular assessment (by the most appropriate local service) anyone with TLoC who also has any of the following
    • an ECG abnormality
    • heart failure (history or physical signs)
    • TLoC during exertion
    • family history of sudden cardiac death in people aged younger than 40 years and/or and inherited cardiac condition
    • new or unexplained breathlessness a heart murmur
  • Consider referring within 24 hours anyone aged older than 65years who has experienced TLoC without prodromal symptoms

Advice for people waiting for a specialist assessment

  • Driving: advise all people who have experienced TLoC that they must not drive while waiting for specialist assessment. After specialist assessment, the healthcare professional should advise the person of their obligations regarding reporting the TLoC to the Driver and Vehicle Licensing Agency (DVLA)
  • Advise people waiting for a specialist cardiovascular assessment:
    • what they should do if they have another event
    • if appropriate, how they should modify their activity (for example, by avoiding physical exertion) and not to drive
  • Offer advice to people waiting for a specialist neurological assessment as recommended in The epilepsies: the diagnosis and management of the epilepsies in adults and children in primary and secondary care (NICE clinical guideline 20)

advice for people waiting for a specialist assessment
advice for people waiting for a specialist assessment

© NICE 2010. Transient loss of consciousness ('blackouts') in over 16s. Available from: www.nice.org.uk/guidance/CG109. All rights reserved. Subject to Notice of rights.

NICE guidance is prepared for the National Health Service in England. All NICE guidance is subject to regular review and may be updated or withdrawn. NICE accepts no responsibility for the use of its content in this product/publication. 

First included: October 2010.