The ‘R’ in EMDR stands for ‘reprocessing’, essentially changing the way that your brain stores memories around trauma. By accessing the traumatic memory in a specific way and then using an outside stimulus (usually visual, hence the ‘eye movement’ part of the acronym) the feelings around the memory will decrease in intensity. You may still experience a stress response around specific triggers such as smells or sounds, but they will be much milder. After desensitization, new and positive feelings can be associated with the memory instead.
Although EMDR is commonly used to treat PTSD, many people have found it helpful with other mental health conditions such as anxiety and depression.