Experiencing a concussion (or mild traumatic brain injury) can be a disorienting and uncomfortable experience, with symptoms including headache, dizziness, confusion, double or blurry vision, light sensitivity, and ringing in the ears, among many others. One less talked-about but equally troubling symptom is nausea. If you’ve found yourself feeling queasy after a head injury, you’re not alone. This blog aims to shed light on why nausea often accompanies a concussion and offers practical advice on how to manage it.
Nausea can occur both immediately following the initial injury in the acute symptomatic phase, as well as some time afterward. Additionally, nausea can be short-lived and resolve in a matter of hours or days, or can linger for much longer following a head injury. In the latter, patients are typically suffering from persistent concussion symptoms (also referred to as post concussion syndrome or post concussive syndrome), and their nausea will likely be provoked by specific activities or situations. Persistent nausea can be extremely unpleasant for patients, and accessing early treatment is critical to ensuring the cause of their symptoms is identified and treated accordingly.
Nausea and vomiting are symptoms that may occur together when we are feeling unwell, but it’s important to understand that vomiting after a head injury can sometimes be a red flag indicating something more serious such as a brain bleed, pressure from swelling in or around the brain, or other serious brain injury.
Some studies have shown that a single isolated episode of vomiting after a concussion is unlikely to be the result of a serious brain injury, especially when not accompanied by other concerning symptoms. However, it is generally better to proceed with an abundance of caution. If you experience persistent vomiting after a concussion, or vomiting that is accompanied by other symptoms such as worsening headache, one dilated pupil, weakness or numbness in the face or extremities, slurred speech, bruising around the eyes, seizure or loss of consciousness, you should seek medical attention immediately to rule out a more serious and potentially life-threatening injury.
Nausea is quite complicated because it’s subjective, while vomiting is an objective, observable reflex in the body. To demonstrate the complexity, below is an image from a 2021 paper looking at the mechanisms of nausea and vomiting (emesis). Don’t worry, though, we’re going to keep it simple and concussion-focused here.
Zhong, W., Shahbaz, O., Teskey, G., Beever, A., Kachour, N., Venketaraman, V., & Darmani, N. A. (2021). Mechanisms of nausea and vomiting:current knowledge and recent advances in intracellular emetic signaling systems. International journal of molecular sciences, 22(11), 5797.
Following a concussion, in particular, there are several factors that contribute to nausea. Understanding these can help you manage the symptoms more effectively.
The inner-ear is home to something called the “vestibular system”, which provides information to our brain to help it understand things like our position in space, and the relative movement of our body or the environment around us.
Vestibular dysfunction involves issues with the inner ear and corresponding brain areas responsible for processing and integrating the information that comes from it. When these systems are disrupted due to a concussion, you may experience vertigo or dizziness, which can lead to nausea. Imagine being on a spinning ride at an amusement park—when you step off, the world keeps spinning, and your stomach turns. Vestibular dysfunction produces a similar effect, but without the fun part. In some cases of vestibular dysfunction, your brain may rely more heavily on the visual system (your eyes), which can cause an increased sensitivity to motion in your visual field, leading to symptoms like headache or nausea.
Nausea that is caused by vestibular dysfunction may arise in situations such as riding as a passenger in vehicles, being in busy places like grocery stores and shopping malls, navigating crowds, or making quick bending or turning movements of the head or torso such as when looking over your shoulder, or rolling over or sitting up in bed.
Traumatic brain injuries can cause dysfunction in our visual system by disrupting the neurological pathways between our eyes and the regions of the brain responsible for processing visual information and controlling our eye movements.
Some common causes of nausea associated with dysfunction of the visual system include difficulty with smooth pursuits (eye tracking, or the ability to fixate on and follow an object as it moves through space), saccades (the ability to make larger, faster jumps between two points in our visual field), or binocular vision (the ability of the eyes to work together to aim at the same point in space, especially at close distances).
Nausea caused by dysfunction of the eyes and the associated visual pathways in the brain can arise when doing things like reading, driving, watching television, or watching live events like a sporting match.
The autonomic nervous system (ANS) controls involuntary bodily functions like heart rate, breathing rate, blood pressure, and digestion. A concussion can disrupt this system, leading to what’s known as autonomic dysfunction. This disruption can result in symptoms such as lightheadedness, intolerance to exercise, and—you guessed it—nausea. Your body’s wiring gets a little scrambled, making it difficult to maintain a stable internal environment.
It is common for the sympathetic nervous system, our body’s “fight or flight” mode, to be more activated following a concussion, and the parasympathetic nervous system, our “rest and digest mode”, to be more suppressed.
Alterations in breathing patterns can lead to reduced oxygen and increased carbon dioxide concentrations in the blood, leading to nausea.
Poor control over blood flow to and blood pressure within the brain can lead to symptoms like nausea. These commonly occur during physical activity when blood flow demands throughout the brain and body change from their resting state.
Disrupted control of our digestion system via autonomic dysfunction can also lead to nausea, as it may lead to reduced intestinal motility (the contraction of our intestinal muscles to move food through the digestive system) and impaired digestive processes.
If symptoms worsen following physical activity, sometimes even light exercise, it is often an indication of dysregulation of the autonomic nervous system.
Issues with the vagus nerve can often lead to symptoms of nausea. This is because the vagus nerve, the so-called “powerhouse” of the parasympathetic nervous system, directly communicates with the stomach and intestines, helping to control the digestive process. When the nerve is irritated or damaged, or not functioning optimally, it can disrupt normal digestive functions, leading to feelings of nausea. Because the parasympathetic nervous system is often suppressed -while the sympathetic nervous system is more activated- after a concussion, issues with vagus nerve function are common.
Believe it or not, a concussion can affect your gut. The brain-gut connection means that a head injury can lead to inflammation in your digestive tract and alter the gut microbiome—the community of bacteria living in your intestines and responsible for helping you digest food properly. This imbalance in the gut microbiome, as well as the inflammation in the gut, can result in digestive issues, including nausea, making it a literal gut-wrenching experience. Nausea that occurs after eating is more likely to be a result of gut inflammation and microbiome changes.
Almost all of us have certainly experienced the uncomfortable feeling of “butterflies” in our stomach, usually when we’re particularly nervous or worried about something. Changes in mental health after a concussion are not uncommon, but can often go overlooked when it comes to treatment and recovery. When our brain is “stuck ” in fight or flight mode, it can lead to increased stress and anxiety, which can sometimes lead to nausea. Additionally, when symptoms of a concussion persist for longer periods of time, we may get stressed, nervous or anxious about situations or environments that we know tend to trigger our symptoms, resulting in that all-too-uncomfortable feeling of “butterflies”, or nausea.
In some instances, people can develop migraine headaches after a concussion, and the severity of the pain experienced with these headaches can lead to nausea, as well as increased sensitivity to light or noise. It’s important to note that if you are experiencing regular, severe headaches following a concussion, you should speak with an experienced healthcare professional as they may want to order tests or imaging to rule out a more serious injury to the brain.
Nearly every concussion injury is accompanied by some degree of neck injury, or whiplash. This is because the amount of force that’s required to cause a concussion is more than 15x greater than what’s needed to cause a whiplash injury to the neck. Nausea is a well-established symptom of whiplash injuries, due in part to the impaired ability of the neck’s somatosensory systems–made up of small receptors that detect the movement of joints and stretch of muscles–to accurately inform the brain about the body’s position. In some instances this can cause the brain to rely more heavily on the visual system (the eyes) and the vestibular system (the inner ear), which can also contribute to nausea.
Managing nausea after a concussion involves addressing both the symptom and its underlying causes.
The current scientific literature on concussion recovery indicates that accessing treatment early, particularly within the first week following the injury, with providers with up-to-date knowledge and experience in managing concussions, can significantly reduce the time it takes to feel better and see symptoms resolve.
Find an experienced provider here and start your recovery process ASAP!
Visual and vestibular rehabilitation exercises can help retrain your brain to manage balance and eye movements more effectively. These exercises often involve head movements, eye exercises, and balance training. Following a vestibular oculomotor screen (VOMS), a healthcare provider with experience in concussion management will provide you with a customized vestibular therapy plan, if indicated. For those experiencing more complex issues with the visual system, referral to a neuro-optometrist for further assessment and treatment may be appropriate.
Inflammation and gut microbiome imbalances can be mitigated through dietary changes. While not directly related to nausea, eating foods like leafy greens, berries, and fatty fish can help through regulating inflammation. Probiotics and prebiotic foods can also support a healthy gut microbiome. Avoiding processed foods, sugars and alcohol can reduce gut inflammation. Supplements such as magnesium and Omega-3 fish oils may also be recommended to help regulate inflammation. Nausea-specific supplements, like ginger or peppermint, would need to be recommended on an individual basis by your healthcare provider.
Staying hydrated by drinking water and ensuring you’re getting optimal amounts of electrolytes such as sodium, potassium and magnesium, as deficiencies may contribute to feelings of light-headedness, nausea and low energy.
In some cases, over-the-counter medications like antihistamines or prescribed medications may be helpful to manage nausea if it is persistent or severe, though it will not address the root cause of it. Additionally, some medications may have undesirable side-effects. As such, you should always consult your doctor before starting any new medication, and it is important to understand that this approach should only be used to manage or mitigate symptoms while the underlying root cause is treated.
Exercise has been shown to be one of the most effective and evidence-based treatments for concussion and post concussion symptoms. However, it is also very common to have symptoms occur with exercise, and therefore it is critical to be assessed by a provider with experience in concussion management to determine what your current threshold is for physical exertion, using something like the Buffalo Concussion Treadmill Test. After this, you should be given guidance on how to exercise safely and in a way that helps to improve your symptoms and exercise capacity over time.
Depression and anxiety, both of which can contribute to nausea, can be common symptoms after a concussion. Prioritizing your mental health by being honest and speaking about how you are feeling with your healthcare provider and your loved ones is important to help ensure you get the treatment that is right for you. Ignoring your mental health or trying to “bottle it up” will only make symptoms worse, and cause them to go on for longer. Techniques such as slow breathing, mindfulness, meditation, and prayer can be helpful in calming an overactive and stressed-out mind.
Plain and simple, make sure your healthcare provider examines your neck and offers appropriate treatment for any pain or dysfunction. A combination of manual therapy, therapeutic modalities, exercise, and education is the most effective and evidence-based treatment for neck pain and whiplash.
While nausea can be an uncomfortable and often debilitating symptom of a concussion, understanding its causes can provide a roadmap to effective management. From vestibular rehabilitation to dietary adjustments, several strategies can help alleviate this queasiness. Remember, you’re not alone—many people experience nausea after a concussion, and with the right approaches, you can find relief.
If you have persistent symptoms or need personalized advice, don’t hesitate to reach out to a healthcare professional with experience and up-to-date knowledge in concussion management. Your health is worth it!
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