Collapse is a sudden and often unannounced loss of postural tone (going weak), often but not necessarily accompanied by loss of consciousness.

If the episode was accompanied by a loss of consciousness, the term syncope is used. The main causes are cardiac (e.g. due to irregular heart beat, low blood pressure), seizures or a psychological cause.^[1] The main tool in distinguishing the causes is careful history on the events before, during and after the collapse, from the patient as well as from any possible witnesses. Other investigations may be performed to further strengthen the diagnosis, but many of these have a low yield.^[1]

References

1. ↑ ^{a b} Petkar S, Cooper P, Fitzpatrick AP. How to avoid a misdiagnosis in patients presenting with transient loss of consciousness. Postgrad Med J 2006;82:630-41. PMID 17068273.