Decreases in barometric pressure two to three days before the visit also appeared to trigger headaches, but to a lesser extent.

VOA: special.2009.03.18

On the other hand, be alert for eating patterns and beliefs that may signal unhealthy behavior, as well as peer pressure that may trigger eating disorders.

CNN: Eating disorders

At the inquest, the firearms expert who had examined the twelve-gauge Mossberg testified that it normally takes five pounds of pressure on the trigger in order to fire the gun.

NEWYORKER: A Loaded Gun

The first departure of a country from the currency union could trigger new financial turmoil across Europe, particularly in larger nations under market pressure such as Spain and Italy.

WSJ: Obama Urges Europe to Act Decisively