Post-traumatic stress disorder is a psychiatric condition that can result from experiencing a terrifying danger.

NPR: Study Tracks Stress Disorder Among Vietnam Vets

He said there could be a range of causes for the condition, such as post-traumatic stress disorder or Parkinson's Disease.

BBC: Sleep violence 'common'

Hall said on Tuesday he could not continue in the post "because of a pre-existing medical condition which is exacerbated by stressful situations and constant travel".

BBC: Hall to step down

How do you respond to the piece from some conservative economist, Feldstein -- Feldstein -- I forget -- Martin Feldstein -- in the Washington Post today that the preexisting condition language in the Democrats' bills would basically encourage people to drop their health insurance.

WHITEHOUSE: Press Briefing

While she is doing fine some six months post-op, she has a major pre-existing condition.

FORBES: ObamaCare's Campaign of Misinformation

Chavez was in stable condition Wednesday, according to a Twitter post from his son-in-law, who is also Venezuela's technology minister.

CNN: STORY HIGHLIGHTS

Launched in a post-conscript age, it can be seen as a return to the historical condition that preceded total war.

NEWYORKER: Slaughterhouse

It has the capacity to destroy a target country's electricity grids and so revert a post-industrial, technology-based country such as Israel or the US to a pre-industrial condition.

CENTERFORSECURITYPOLICY: An urgent memo to the next government