Are Your Tweets Feeling Well? (IMAGE) DOE/Pacific Northwest National Laboratory Caption Researchers at Pacific Northwest National Laboratory assigned more than 171 million anonymous tweets an opinion and emotion, such as "positive" and "joy." When visits to a certain health clinics for flu-related illnesses rose, the researchers found that opinion and emotion expressed by Twitter users in those regions also changed. Health workers could one day use this method to get real-time information about health trends. Credit Eric Francavilla / PNNL Usage Restrictions With credit: Eric Francavilla / PNNL License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.