"The blood froze in my veins" or "My blood curdled" – these common figures of speech can be taken literally, according to the latest studies. Indeed, more literally than some of us would like. For it turns out that intense fear and panic attacks can really make our blood clot and increase the risk of thrombosis or heart attack.

PLoS ONE publishes a study showing that inhalation of carbon dioxide (CO2) triggers emotional distress and a panic response in healthy individuals. The findings of the study posit panic as an inborn survival-oriented response. The results may be relevant for a better understanding and the further prevention of emotional disorders.