A concussion is a mild traumatic brain injury (mTBI) resulting from a bump, blow, or jolt to the head, or a hit to the body that causes the head and brain to move rapidly back and forth. This sudden motion can disrupt the brain’s normal function, causing a cascade of temporary symptoms. Vomiting is a recognized physical symptom of a concussion and often serves as an important indicator of the injury’s severity. Although not everyone with a concussion will vomit, its presence after a head trauma is a sign that requires immediate attention and professional medical evaluation.
Vomiting: An Indicator of Concussion Severity
The occurrence of vomiting following a head injury is a significant symptom that medical professionals use to assess the potential seriousness of the trauma. Simple nausea is a common symptom in many mild concussions. However, actual vomiting, especially if it is repeated, elevates the level of concern and suggests the possibility of a more serious condition.
A single episode of vomiting may occur after a mild head trauma. Persistent or repeated vomiting is a key red flag that can signal increased pressure inside the skull. This increased intracranial pressure can be caused by swelling or bleeding within the brain tissue, which requires immediate medical intervention. Observing the frequency of vomiting is therefore a way to gauge the urgency of the situation, though even a single instance should prompt an assessment. Vomiting may also be a predictor of a skull fracture, which increases the necessity of medical imaging.
The Neurological Link: Why Head Trauma Causes Vomiting
A blow or jolt to the head causes the brain to move within the skull, which can damage nerve cells and disrupt normal brain function. This sudden disruption can lead to rapid fluctuations in the pressure exerted within the skull, known as intracranial pressure, which is one mechanism that triggers the emetic response. The brain’s reaction to the injury can also stimulate the central nervous system, increasing the sensitivity of the vomiting center.
Vomiting can also result from the trauma affecting the vestibular system, which is the part of the inner ear that controls balance and coordination. Damage to this system can cause dizziness and vertigo, which gives the brain a false sense of motion similar to motion sickness. The injury can also trigger activation of the autonomic nervous system, which may further contribute to symptoms like nausea and vomiting.
Immediate Medical Red Flags Requiring Emergency Intervention
While many concussion symptoms can be managed with rest, certain signs mandate an immediate trip to the emergency room to rule out a severe brain injury, such as a brain bleed. Persistent or worsening vomiting is at the top of this list, often defined as throwing up three or more times. Any loss of consciousness, even if brief, is also a serious indicator that the brain has been significantly impacted.
Other signs of a more serious condition include a severe headache that worsens over time or does not improve with non-prescription pain relief. A change in neurological function is also highly concerning, such as slurred speech, weakness or numbness in the arms or legs, or a noticeable loss of balance. Visual changes like unequal pupil size, blurred vision, or double vision are additional red flags. Increasing confusion, restlessness, agitation, or being difficult to wake up are signs of a deteriorating condition that requires emergency care.
Steps for Monitoring and Recovery After Head Injury
Once a serious trauma has been ruled out by a medical professional, the focus shifts to careful monitoring and recovery. It is important that the injured person is not left alone for at least the first 24 hours, allowing a caregiver to watch closely for any worsening symptoms or the emergence of red flags. Rest is a cornerstone of initial recovery, but guidelines now recommend “relative rest,” meaning complete physical and mental rest is limited to the first 24 to 48 hours.
During this initial period, individuals should avoid activities that require intense concentration, such as extensive schoolwork, video games, or excessive screen time. Instead, they should prioritize sleep and short rest breaks during the day to allow the brain to heal. After the first 48 hours, light physical activity, such as walking, can be gradually reintroduced as tolerated, as long as it does not cause symptoms to worsen. A gradual return to normal activities, including school or work, should only happen after symptoms have resolved and following the guidance of a healthcare provider.