Dear Doctor: I tripped while I was out running a few months ago and got pretty banged up, including a knock to the head. My wife worried about a concussion and wanted me to see a doctor. How do you know if you have a concussion?
Dear Reader: A concussion is a type of brain injury that can occur when a force is powerful enough to cause the head, along with the brain inside of it, to shake quickly back and forth. This can result from the type of direct impact you experienced when you fell during your run. It may also be caused by an indirect force that's powerful enough to make the head whip back and forth, as can happen during a tackle or when you're rear-ended in your car at high speed.
Your brain is basically a passenger within your skull. When something causes your head to stop short or suddenly change direction, your brain continues moving. It bounces and twists and bumps into the interior surfaces of the skull. A concussion results in a chemical change within the brain, along with bruises, tears or injury to the soft and fragile tissues. Because it's not life-threatening, concussion is typically referred to as a mild traumatic brain injury, or TBI. However, the effects can be serious.
When you have a concussion, symptoms may show up right away, or they can develop over a period of hours or days. Immediately after a concussion, a person may appear dazed or bewildered. They may not immediately be aware of what happened, and it's possible they won't recall the moments leading up to the injury. Some people become clumsy, and they may have trouble understanding and following directions. Physical symptoms can include headache, feeling nauseated, vomiting, a feeling of pressure within the skull, blurred or double vision, ringing in the ears and problems with balance and coordination. Some people may develop a sensitivity to external stimuli, including light and sound. The person may report feeling slow or groggy or just generally not OK. A brief loss of consciousness immediately after impact is possible.
Someone with a suspected concussion should seek medical care. You'll be asked for details about the accident, as well as any symptoms. It's important to also share information about any medications and supplements, as some can increase risk of bleeding. Diagnosis includes a neurological exam that checks vision, hearing, strength, balance and coordination. Cognitive tests are used to evaluate memory, recall and concentration. It's possible that someone would be asked to stay overnight in a hospital for observation. In some cases, brain imaging tests may be considered.
In 2018, the U.S. Food and Drug Administration approved a blood test to evaluate concussion. It measures levels of two protein biomarkers that the brain releases into the blood within 12 hours of a head injury. It's not a diagnostic test for concussion, but it does help predict which patients will have injuries that will be visible in a brain scan.
With 3.8 million reported concussions per year, this is a common injury. It's also a potentially serious one. It's important, so we'll say it again: If you suspect a concussion, seek medical care.
Eve Glazier, M.D., MBA, is an internist and associate professor of medicine at UCLA Health. Elizabeth Ko, M.D., is an internist and assistant professor of medicine at UCLA Health.