Laughter-induced syncope.

This case report describes a 58-year-old man who is otherwise healthy but has periodic episodes of syncope which only happen when he laughs vigorously. This occurs suddenly with no prodrome, so the patient has no time to react and is unable to brace himself when he falls. The case is one of the very few described in the medical literature, most of which have similar presentations and findings on subsequent investigation. Recognition of the typical presentation, in the absence of more serious causes of syncope, may avoid extensive and expensive evaluation.