The force of laughing can dislocate jaws,
prompt asthma attacks,
cause headaches, make hernias protrude.

It can provoke cardiac arrhythmia, syncope
or even emphysema (this last,
according to a clinical lecturer in 1892).

Laughter can trigger the rare but possibly grievous
Pilgaard-Dahl and Boerhaave’s syndromes.

There are choking hazards,
such as ingesting food during belly laughs.

We don’t know how much laughter is safe.

There’s probably a U-shaped curve:
laughter is good for you,
but enormous amounts are bad, perhaps.

Taken from Who Says Laughter’s the Best Medicine? in The New York Times, 20 December 2013. Submitted by Howie Good.