To diagnose an injury to the head, medical providers use the Glasgow Coma Scale, known as the GCS. This test has 15 points and assesses the mental status of a patient. If a patient scores high on the test, it means he or she has a less severe head injury. Those who score low are most severely injured.
A doctor will also need to know what happened. If you can’t remember but have a witness, that person may be able to explain, so the physician can have a better idea of the impact to your head and brain. Once this is understood, the doctor may begin to evaluate nerve functions and eye movements, along with other important reactions.
CT scans and MRIs can be beneficial when trying to diagnose a head injury. If the imaging tests are performed, they will be able to show structural damage as well as bleeding, clotting and swelling. This can help not only show how severe an injury is but also how well it is healing over time. Patients often don’t receive MRI scans until they are stable, while CT scans will likely be ordered as soon as a patient is able to have it.
Source: Healthline, “Head Injury,” accessed Feb. 04, 2016