What Happens to the Brain When You Get a Concussion?

When you hear the word “concussion,” you might think of a hard hit to the head or someone briefly losing consciousness. But what actually happens inside the brain during this kind of injury?

A concussion is a mild traumatic brain injury (mTBI) that occurs when a sudden blow or jolt causes the brain to bounce, twist, or shift within the skull—sort of like an egg yolk inside an eggshell. Your brain is cushioned by cerebrospinal fluid (CSF) and is protected by your skull, but it’s not firmly attached— it floats. That means when your head goes through something like a fall, car accident, sports collision, or anything with sudden force, the brain can move rapidly and hit the inner walls of the skull. This can lead to temporary chemical imbalances, disrupted neural pathways, and microscopic damage that typically won’t show up on standard imaging such as a brain MRI or CT scan.

More specifically, following a concussion, a “metabolic cascade” occurs in the brain. In simple terms, this means the brain’s normal balance of chemicals gets thrown off. When the brain is jolted, it triggers a chain reaction: brain cells release too many chemicals too quickly, and the brain uses up energy much faster than usual trying to restore order. At the same time, it’s harder for the brain to get the fuel (like glucose) it needs to recover.

This chemical chaos is what can lead to many of the classic concussion symptoms. Some of the most common include headaches, dizziness, confusion, memory issues, sensitivity to light or noise, fatigue, irritability, nausea, and balance problems. Some people experience symptoms immediately, while others may notice them for hours or days after the injury. It’s important to understand that even if someone doesn’t lose consciousness, they can still have a concussion. And just because you can’t “see” a concussion doesn’t mean it’s not serious.

The good news? Concussions heal with proper initial rest and gradual return to activity with guidance from a medical professional who is knowledgeable in concussion management. At Horizon Neuropsychological Services, our concussion clinic offers expert evaluation, personalized treatment plans, and ongoing support to guide your recovery every step of the way.

Understanding what happens in the brain during a concussion is the first step toward recognizing the signs, knowing when to seek help, and making informed decisions as the brain recovers. Should a concussion occur, be sure to contact our concussion clinic at 720-242-7533 to make an appointment as soon as possible after an injury to promote a safe and timely recovery from concussion.