If you’ve been involved in a car accident, pay attention to the symptoms of potential delayed onset injuries, such as headaches, neck or shoulder pain, back pain, numbness, abdominal pain, and PTSD. Even if you do not experience pain immediately and you feel fine, you may have still suffered a 'delayed onset' injury in a car accident. If you’ve been involved in a car accident, seek medical attention and follow the recommendations of first responders at the scene.