OCD takes a huge toll on the body, both mentally and physically. Emotional pain always has a physical component. If you are having a bout with OCD or any co-related conditions, such as depression, generalized anxiety, attention deficit disorder, etc., it may help if you notice your physical symptoms. OCD can make you tired, achy, nervous, and depressed. You may get headaches or stomachaches.
If you are suffering from severe OCD please realize that you need to be kind to your body. If possible, rest up and get as much sleep as you can. Also, make sure you are getting proper nutrition and are well hydrated. Paying attention to the physical body will help the mind. They are not separate, and when one is affected, so is the other.