Anxiety can be a good thing—in small amounts. A little bit of anxiety can prompt you to study for a big test or get to work on time. Too much anxiety, however, can damage your physical or emotional health. Feeling extreme fear or worry that’s out of proportion to the actual risk can be a problem, particularly if it interferes with daily life. There are many types of anxiety disorders, including obsessive-compulsive disorder, panic disorder, and post-traumatic stress disorder (PTSD).