Systematic desensitization works by three steps. In the first step, the individual creates what is called an anxiety hierarchy. The individual will be asked to list a number of items that produce anxiety, ranked by the severity of the induced anxiety. Second, the individual is trained in muscle relaxation. They’re taught how to consciously relax their muscles. Finally, the individual is presented with the items from their anxiety hierarchy, starting with the least anxiety-stimulating stimulus. Each time the individual is presented with an item from their anxiety hierarchy, they are trained to practice muscle relaxation. 

The reason why muscle relaxation is used in systematic desensitization is because when your muscles are relaxed, you can’t experience anxiety in the same way that you can when the body is tense. The idea is that when an individual practices muscle relaxation, they respond less to the anxiety-producing stimulus. Then, after a few repetitions, the individual gets to a point where anxiety-producing stimulus no longer produces any anxiety. 

Once one anxiety-producing stimulus is overcome, the process is repeated with the next item in their anxiety hierarchy. This process is then repeated over and over again until the entire list of items has been conquered.