Many people do not feel significant pain or discomfort until 48 to 72 hours or longer after an accident. This is not uncommon, and there are many reasons for the delayed onset of pain, including post-accident adrenaline and the nature of inflammation and swelling.
The delay of pain onset after trauma is common, so much so that most EMS personnel and police officers who respond to the scene of an accident will advise all parties to seek emergency help later if and when pain symptoms emerge. Just because a person does not feel hurt enough to be transported to an emergency room from the scene of an accident does not mean she was not injured in the accident. In practice, I have seen numerous clients who feel relatively fine for several days before the significant pain begins. Sometimes their pain onset is only the beginning of a long process that leads to the diagnosis of severe muscular strains, spinal injuries, or shoulder tears. If you begin experiencing intense or increasing pain after an accident, go to the emergency room or see a doctor immediately. Early diagnosis and care is important, and taking a "wait and see" approach with your health and pain may lead to unnecessary suffering and worse problems down the road.