When left untreated, hypertension can cause life-threatening consequences like stroke or heart attack. Find out what's really happening in your body when your heart is working overtime due to high blood pressure. Comments on this video are allowed in accordance with our comment policy: http://www.cdc.gov/SocialMedia/Tools/CommentPolicy.html This video can also be viewed at http://streaming.cdc.gov/vod.php?id=66b8b316392cfff9c48522ac804fb8da20120831100737569