also check your page load times. if it takes a long time to load the page users are more likelly to bounce
Normally bounce rate increases when users click on a particular page expecting to find something they hoped they would. If they do not find anything then they click away hence increasing the bounce rate. To decrease bounce rate you would want to better the content first.
Well, pretty interesting discussion I must say.. but let me explain.. if you GA data shows 85% bounce rate, that doesnt mean your site has a problem.. bounce rate are of two types.. Actual Bounce rate and Standard bounce rate.. you might want to read one of my articles on bounce rate: http://www.seozy.com/bouncerate-how-does-it-affect-your-seo/