Diagnosing a concussion is not a hard and true science. Since there is no definitive test for a concussion, doctors must rely primarily on observed or self-reported symptoms. Yet not all concussions come with obvious symptoms, and in many other cases, symptoms that were initially present will have passed by the time a doctor does his exam. Symptom reporting is also a highly subjective way of gathering evidence. What patients report or how different people experience pain varies widely from one patient to the next, and there is also significant potential for answers to be swayed by suggestion. For example, if I asked you “Do you think you need to sneeze?” or “Do you have a headache?” those questions alone might make you think you need to sneeze or get you thinking about headaches.

There isn’t even agreement among experts on how to define a concussion in children. Parents need to be aware of this when seeking a concussion diagnosis. Sometimes doctors can discern rather definitively that a child has suffered a concussion; other times the basis for diagnosis will be much more shaky.

What will happen when I take my child to the doctor for a concussion?
Most doctors will perform a basic neurological exam to check a child’s vision, hearing, reflexes and balance. They’ll also usually ask a series of questions about how the injury occurred and whether a child lost consciousness at any time during or after the incident. Then they’ll do a symptom inventory like the one listed under the signs of a concussion page.

Unless there is reason to suspect bleeding in the brain or some other serious injury, doctors will not order a brain scan. The effects of a concussion are too subtle in most cases to show up on a CT scan, MRI, or PET scan. The only reason for such a scan would be to spot a potentially deadly hematoma (brain bleed). But since these are almost universally linked with other symptoms, a doctor will only order one if a child exhibits those specific symptoms. CT scans are heavy on radiation and come with risks of their own, with some studies putting the lifetime increased cancer risk for each CT scan given at 1 in 1,000 (meaning there’s a 1 in 1,000 risk that a CT scan will give your child cancer). So doctors usually avoid this test unless they have a good reason to do it.

How doctors diagnose a concussion
Doctors will typically diagnose a concussion if a person has suffered some type of blow or jolt to the head and is experiencing at least one or two of the well-known concussion symptoms that weren’t present earlier. Sometimes there are clear neurological symptoms that will offer more definitive proof of a concussion, such as pupil dilation, delayed pupil reflexes, balance problems or delayed reaction time. But these don’t show up in every case.

Fooled you: Concussion-like symptoms that can lead to a false diagnosis
Unfortunately, there are any number of things that can cause concussion-like symptoms, such as…

• Migraines

  • The flu or other viruses

  • Post-traumatic stress

  • Altitude sickness

  • And so on.

  Which means that it’s possible for a child to knock their head and then experience concussion-like symptoms a day or two later that have nothing to do with a concussion. That said, when in doubt, parents should err on the side of caution and approach the situation as if it is a concussion.