In addition, loneliness raises levels of the circulating stress hormone cortisol and blood pressure, with one study showing that social isolation can push blood pressure up into the danger zone for heart attacks and strokes.<ref>[http://www.livescience.com/18800-loneliness-health-problems.html | In addition, loneliness raises levels of the circulating stress hormone cortisol and blood pressure, with one study showing that social isolation can push blood pressure up into the danger zone for heart attacks and strokes.<ref>[http://www.livescience.com/18800-loneliness-health-problems.html |