Doctors could be failing to identify heart disease, epilepsy or other serious underlying health issues which cause some people to suffer blackouts, according to a health watchdog.
Most commonly characterised by fainting, blackouts are a temporary loss of consciousness before making a complete recovery. Family doctors may be missing serious reasons why people suffer from them, said the National Institute for Health and Clinical Excellence (NICE).
NICE has called for doctors to treat all cases of blackouts seriously until a diagnosis is made, and to refer to specialists if there are any doubts.
Approximately half of Britons will suffer blackouts during the course of their lives and, in most cases, it is a simple faint. Fainting can be brought about by standing for a long time, failing to eat properly, feeling anxious or stressed, or a sudden unpleasant experience or sight.
The guidelines also call on doctors to look out for possible neurological conditions and symptoms, such as jerky limbs during the blackout, a person biting their tongue or experiencing confusion or disorientation when they come round.
Fergus Macbeth, Director of the Centre for Clinical Practice at NICE, said: "Although transient loss of consciousness is a very common symptom that the NHS deals with on a daily basis, its diagnosis can often be inaccurate, inefficient and delayed.
"For example, some people with epilepsy may also have a heart problem which has caused them to black out, which could initially be overlooked as the healthcare professional may believe that he or she already has the correct diagnosis."