In a car accident, everything happens so quickly that you may not remember all the details. It is also possible some details are missing because you bumped your head and suffered a brief loss of consciousness. Because you have no memory of the blow, you may not realize a bruise is an indication of a more serious injury.
Besides the outward pain of the bruise, you could suffer damage to the inside of your skull that will not cause symptoms for several days, or even weeks. How is this possible?
What happens inside the skull
Ruptured blood vessels cause bruise discoloration. When your brain collides with your skull, either from a direct blow to your head or from the violent motion of whiplash, it can cause that same bruising. Inside the skull, bleeding and swelling cause a build-up of pressure that cuts off the blood supply to the brain.
As blood collects, it can damage an area of the brain that did not even sustain injury in the initial blow. A blood clot may also dislodge and move through the blood vessels rather than disintegrate as it should. The moving clot can block blood flow, cut off oxygen to the brain or cause a stroke.
When one injury leads to another
After a head injury, it is vital to avoid activities that may lead to another injury. If your job involves physically or mentally demanding activities, you may want to talk to a doctor about whether you should limit these until your brain has healed. It may also be dangerous for you to operate heavy machinery or drive until your doctor gives you the all-clear.
Why is it so important to avoid a second blow to the head? You could sustain second-impact syndrome if you receive a second concussion before the first is completely healed. This condition causes life-threatening bleeding and swelling of the brain.