Most people think a concussion is simply a “bruise” to the brain. In reality, it sets off a cascade of events that temporarily disrupts how brain cells communicate, produce energy, and heal.
When the head experiences a sudden impact, the brain rapidly accelerates and decelerates inside the skull. This mechanical force stretches delicate brain cells—especially their long communication fibers called axons. Even when the cells don’t die, they become temporarily “leaky,” allowing important minerals such as potassium, sodium, and calcium to move across the cell membrane in ways they shouldn’t.
This loss of balance creates electrical chaos throughout the brain. Neurons begin firing abnormally, releasing excessive amounts of the neurotransmitter glutamate, which allows even more calcium to enter the cells. While calcium is essential in small amounts, too much becomes damaging. It activates enzymes that begin breaking down the neuron’s internal support system, disrupting communication between brain cells and impairing the transport of nutrients along axons.
At the same time, the brain works overtime trying to restore normal electrical function. Tiny sodium-potassium pumps consume enormous amounts of ATP (the cell’s energy currency) to rebalance these ions. Unfortunately, just when the brain needs the most oxygen and glucose to produce that energy, cerebral blood flow often falls by 20–50%. This creates what researchers call the neurometabolic energy crisis—the brain’s energy demand rises dramatically while its ability to deliver fuel is temporarily reduced.
As a result, brain networks no longer communicate with their usual precision. Rather than functioning like a well-rehearsed orchestra, the injured brain becomes more like an orchestra without a conductor—some neurons fire too much, others too little, and the timing between them becomes disrupted. This loss of coordination helps explain why people commonly experience brain fog, dizziness, slowed thinking, visual problems, balance difficulties, headaches, fatigue, and autonomic symptoms after a concussion.
Although the initial electrical imbalance often improves over hours to days, recovery doesn’t necessarily end there. Damaged mitochondria may produce less energy, stretched axons may conduct signals less efficiently, inflammation can interfere with communication between neurons, and blood flow regulation may remain impaired. The brain is still capable of healing, but it often needs additional time, energy, and the right environment to fully recover.
This understanding also helps explain why many concussion symptoms persist despite normal CT scans or MRIs. Standard imaging is excellent at detecting bleeding or major structural injuries, but it cannot see many of the microscopic functional changes occurring within brain cells and their connections. In other words, the brain may look normal on imaging while its communication networks are still working far below their normal capacity.
The encouraging news is that the brain possesses an incredible ability to repair and reorganize itself. Supporting oxygen delivery, improving cellular energy production, reducing inflammation, and promoting healthy blood flow all help create an environment where these injured neural networks can recover. At New England Hyperbarics, this is one of the reasons we use medical-grade deep pressure hyperbaric oxygen therapy—to help supply the oxygen the healing brain needs to recover, whether a recent brain injury or from years ago, HBOT can help.
