How Long Does A Concussion Last?
A concussion is a ‘functional injury’ resulting in the disruption of normal brain function. This occurs following a rapid acceleration of the brain inside the skull, caused by an impact to the head, neck or elsewhere on the body with forces transmitted to the brain. There are 22 possible symptoms of concussion, and these can last anywhere from days to weeks and, in some cases, even longer.
‘How long does a concussion last’ is a very difficult question to answer as every concussion is different. In order to understand the duration of a concussion and what needs to happen for a full recovery, you must first understand what is going on inside your brain, metabolically speaking.
What’s Going on in There? The Neurometabolic Basis of Concussion
Upon initial injury, the neurons in your brain become stretched. Setting off a chain of events known as the “neurometabolic cascade”[1,2].
Let’s take a closer look at what’s really going on in there:
- Following the stretching of your brain cells, an exchange of chemicals occurs resulting in the sudden excitation or firing of neurons and the subsequent release of neurotransmitters including glutamate.
- Glutamate activates brain cell receptors that cause a greater influx of calcium into the cell.
- Additional calcium inside the cells prevents effective cellular respiration, which is the most efficient means of energy production.
- A massive amount of energy is required to help restore the ion imbalance that now exists, and due to energy being supplied by less efficient means, a large energy deficit is created.
- The entire cascade leads to cellular dysfunction, and that means YOU are not functioning like you did prior to the injury.
So your brain is excited, neurons are misfiring and your system needs to work overtime to reestablish ionic equilibrium or homeostasis. This rebalancing requires a huge amount of energy. But remember, the stretching of the cells instigated events that not only depleted the system, but caused the brain to create energy by less efficient means. Your brain is using all of this energy to right itself, but it simply can’t get the energy it needs, so you develop an energy deficit.
And here’s where, if you’re not working with a therapist trained in concussion management, you can get into a bit of trouble. Because after a week or so, maybe some of your symptoms have gone away and you’re starting to feel better. But your brain is still NOT fully recovered. If at this point you try and return to your sport, you risk further injury because your brain is still in a vulnerable place, neurometabolically speaking.
Why Symptoms Should NOT Guide Your Recovery
Recovery from a clinical standpoint is different from recovery from a physiologic standpoint. This was highlighted in the International Consensus Statement on Concussion in Sport. The clinical time for recovery is when your symptoms subside. The physiologic time for recovery is when your brain actually recovers metabolically. Unfortunately, these two things do NOT coincide, making concussion difficult to manage – particularly with athletes.
Typically, initial concussion symptoms last for a period of 7 – 10 days. Once these symptoms have abated, an athlete may think they are “all better.” And their coach or therapist may sign off and send them back out onto the field or ice.
But a concussion is a functional injury, meaning brain function has been altered. There is no golden test (imaging, blood, saliva or otherwise) that enables healthcare professionals to determine if you have fully recovered from your concussion. As such, functional testing is currently the best means for concussion management teams to help build a clinical picture and ascertain when it is safe for an athlete to go back to sport.
Additional testing provides important insight to the overall clinical picture during recovery:
- If the symptoms are gone, is the functional deficit gone as well?
- Is the athlete able to increase their heart rate and blood pressure safely without the return of symptoms?
- Is the athlete’s reaction time, balance and ocular motor speed back to where it was before the injury?
- Is their neurocognitive function back to where it needs to be?
Functional testing can ultimately help to determine whether an athlete is still in or out of that vulnerable compromised metabolic state. If they are still vulnerable and they go back to playing, there is not only potential for a second concussion, but also an injury with additive effect and prolonged recovery if not more severe and permanent outcomes.
Persistent Concussion Symptoms
Persistent Concussion Symptoms, previously known as Post-Concussion Syndrome (PCS), occur when concussion symptoms persist beyond the expected recovery period after the initial injury. We mentioned that symptoms typically subside within a 7 to 10 day timeframe, however sometimes they can linger. What studies are now showing is that the sooner you get treatment for your concussion after the initial injury, the less likely you will be to experience persistent concussion symptoms or a prolonged recovery. The fact is, when not addressed PCS can last for weeks, months and even years.
The studies that have been done on concussions have found that full metabolic recovery of the brain typically occurs at some point between 22 and 45 days, while most people’s symptoms will subside within the first 7 to 10 days. And, roughly 30% of people go on to have symptoms beyond this period, which is why we call it persistent concussion symptoms.
The science is now indicating that the #1 predictor for recovery is time to initial assessment and treatment. The sooner you receive treatment from knowledgeable concussion practitioners who can guide you through recovery, focusing treatment on functional testing and not just symptom abatement, the more likely you will be to recover quickly and fully before returning to sport.
A retrospective study completed by Kontos and colleagues at the University of Pittsburgh in 2020, examined the association from time of injury to the first clinical assessment or presentation and how this can effect recovery time in an adolescent and young adult population . The study found that athletes evaluated within one week of injury recovered in a mean of 20 days faster than those seen within a 2-3-week timeframe.
The below study excerpt serves to highlight the importance of engaging in clinical care as soon as possible!
“One reasonable explanation for this difference is the earlier initiation of active rehabilitation strategies including exertion progression and opportunity to start structured physical therapies (example – vestibular, visual and cervical). Further, without clinical guidance and behavioural management recommendations post injury, athletes may have been engaging in counterproductive recovery strategies such as strict rest or excessive physical activity. This explanation is supported by the fact that athletes recovered in a similar amount of time after the first evaluation. As such, the days before initial evaluation were primarily accounting for the longer recovery duration rather than the time in which the patients were under clinical care with a treatment plan” .
In a similar analysis, Complete Concussion Management (CCMI) as the largest global concussion network in conjunction with McMaster University, worked to review the predictors of recovery through a prospective analysis of the CCMI database. Clinical data showed that the number one predictor for recovery time was how quickly a patient was assessed by a clinician trained in concussion management .
Earlier presentation to clinical care can help to mitigate the number of athletes experiencing prolonged recovery!
How long does a concussion last? That’s not really the right question. A better question to ask is, “How do I know when it’s safe for me to go back to my sport?” And the answer to that is, “When comprehensive testing concludes your brain is metabolically functioning at full capacity as it did before your injury.”
While symptoms may disappear within the first week or two after the injury, your brain is still in a state of vulnerability due to ongoing metabolic changes. And when your brain is vulnerable, YOU are vulnerable and prone to further injury.
If you have suffered a concussion but have not yet met with a healthcare provider trained in concussion management to guide you through a personalized recovery plan, we encourage you to do so. Remember, the sooner you get treatment, the less likely you will be to experience persistent concussion symptoms.
Complete Concussion Management is a network of trained multidisciplinary healthcare practitioners that collaborate with physicians to co-manage concussion injuries, helping patients and athletes safely return to learn, work and play.
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 Giza, C.C., & Hovda, D.A. (2001). The neurometabolic cascade of concussion, Journal of Athletic Training, 36(3): 228–235.
 Giza, C.C., & Hovda, D.A. (2014). The new neurometabolic cascade of concussion, Neurosurgery, 75(04): S24–S33. doi:10.1227/NEU.0000000000000505
 McCrory, P., Meeuwisse, W., Dvorak, J., Aubry, M., Bailes, J., Broglio, et al. (2017). Consensus statement on concussion in sport: the 5th international conference on concussion in sport held in Berlin, October 2016. British Journal of Sports Medicine. 0:1–10. doi:10.1136/bjsports-2017-097699
 Kontos, A.P., Jorgensen-Wagers, K., Trbovich, A.M., et.al. (2020). Association of time since injury to the first clinical visit with recovery following concussions, JAMA Neurology, 77(4): 435-440. doi:10.1001/jamaneurol.2019.4552
 Pratile, T., Marshall, C., & DeMatteo, C. (2021). Examining how time from sport-related concussion to initial assessment predicts return-to-play-clearance. The Physician and Sportsmedicine. doi:10.1080/00913847.2021.1879603
This information is designed to provide education and awareness. This article is not intended as a substitute for the medical advice of doctors and/or healthcare professionals. The reader should always consult their physician and/or healthcare providers in matters relating to their health, and in particular, with respect to any concussion and/or symptoms that may require diagnosis or medical attention.