The actual impact and moments after your car accident are a blur, but other than feeling shaken up, you do not seem to have any obvious injuries, so you go home. Over the next two or three days, you feel stiff and sore, but with over-the-counter medicine and a couple days off work, you begin to feel better. However, a week or so after the accident, you start having headaches, dizziness, nausea and trouble sleeping. These symptoms may indicate a traumatic brain injury. At this point, you need to get to the doctor right away.
The damage does not stop with a blow to the head
When your head whipped back and forth during the impact, you may have expected whiplash. However, that violent motion may have sent your brain crashing into your skull, bruising the delicate tissues. Like a bruise on any other part of the body, there will likely be swelling. Inside the skull, though, that swelling causes pressure buildup that can lead to a secondary brain injury. The swelling and pressure may not peak right away, which is why you did not experience symptoms until days after the first trauma.
Swelling is not the only potential issue. You could have torn blood vessels inside your skull. Bleeding can also cause dangerous pressure, and a very small tear in a capillary could leak so slowly that you do not experience obvious health problems until a month later. On the other hand, the internal wound could clot as it heals naturally. If that blood clot does not dissolve the way it should, the hardened lump could dislodge, block a blood vessel and cut off oxygen to the brain, leading to a stroke.
One head injury often leads to another head injury
Once you have sustained a traumatic brain injury, you are much more likely to sustain another one in the days and weeks after, before the first injury fully heals. According to the American Association of Neurological Surgeons, second-impact syndrome is often the outcome, and this condition, which involves rapid brain swelling, is frequently fatal.