Although most transient episodes of loss of consciousnes are benign, they may signal serious cardiac or brain pathology or be a symptom of an illness not primarily involving the cardiovascular or central nervous systems.
- Most blackouts are caused by syncope or seizure.
- Syncope and seizure can usually be confidently distinguished by the history.
- Description by a witness to the event is an essential part of the history.
- Syncope is often misdiagnosed as seizure when it is accompanied by convulsive movements.
- Syncope is usually benign and does not need investigation, but when certain features are present, cardiac disorders, especially arrhythmias, should be excluded.
- Seizures have a wide range of causes and affected patients require neurological referral.