A concussion is a temporary brain injury that typically results in a variety of physical, cognitive, and emotional symptoms following a bump, blow, or jolt to the head. While many symptoms appear immediately after the impact, some may take several hours or even days to become noticeable, making continuous observation essential during the first 48 hours. Most people recover fully from these symptoms with appropriate rest, but recognising the signs early is vital for managing the injury safely and ensuring a gradual return to normal activities.
What We’ll Discuss in This Article
- The primary physical symptoms experienced immediately after a concussion.
- Common cognitive and mental changes to look for in the days following an injury.
- Emotional and behavioural shifts that may indicate a brain injury.
- Age-specific symptoms in infants and young children that differ from adults.
- How symptoms evolve over time and the importance of the 48-hour monitoring window.
- Distinguishing between typical concussion symptoms and emergency red flags.
Immediate Physical Symptoms of a Concussion
Physical symptoms are usually the most obvious indicators of a concussion and often occur within minutes of the head impact. A persistent headache is the most frequently reported symptom, followed by feelings of dizziness, nausea, or a general sense of being dazed. Some individuals may experience a brief loss of consciousness, though this is not required for a concussion to be diagnosed. The NHS states that a concussion is a temporary injury to the brain caused by a bump, blow or jolt to the head.
In the moments following the injury, the person may also have blurred or double vision, or they may find that bright lights and loud noises cause them discomfort. Balance problems and a lack of coordination are also common pitch-side or scene-of-accident signs. It is important to note that even if no visible bump or bruise is present on the scalp, the internal movement of the brain can still produce significant physical distress.
Cognitive and Mental Changes to Monitor
Cognitive symptoms refer to changes in how the brain processes information, concentrates, and remembers events. A person with a concussion may describe feeling “foggy” or slowed down, as if their thoughts are moving through water. They may struggle to answer simple questions, have difficulty following a conversation, or seem confused about their surroundings and the time of day.
Memory issues are a hallmark of concussion, particularly amnesia regarding the event itself or the moments just before and after it occurred. These cognitive disruptions are caused by the temporary chemical imbalance and stretching of brain cells that occur during the impact. The National Institute for Health and Care Excellence provides clear guidelines for the assessment and early management of head injuries to identify these functional changes.
Emotional and Behavioural Shifts
A concussion can affect the parts of the brain responsible for regulating mood and behaviour, leading to shifts that may seem out of character. These emotional symptoms can sometimes be delayed and might only become apparent when the person attempts to return to their normal work or social routine. Common changes include increased irritability, feeling more anxious or nervous than usual, or experiencing sudden bouts of sadness or tearfulness.
Changes in sleep patterns are also frequently reported, with some individuals finding they sleep much more than usual, while others struggle with insomnia. These behavioural shifts are often a sign that the brain is under metabolic stress and requires more rest to recover. Caregivers should be alert to any persistent mood changes that do not resolve as the physical symptoms begin to fade.
Symptoms in Infants and Young Children
Recognising a concussion in young children and infants is challenging because they cannot verbally describe how they feel. Instead, parents and caregivers must rely on observing changes in the child’s typical behaviour and physical state. In infants, a primary sign of a head injury can be excessive or inconsolable crying that does not respond to usual comfort measures.
Other age-specific symptoms include a loss of interest in favourite toys, refusal to nurse or eat, and a sudden change in sleeping habits. Toddlers may show a loss of newly acquired skills, such as toilet training or steady walking. Because children’s brains are still developing, they are particularly vulnerable to the effects of a concussion, and any suspected injury in this age group should be assessed with extra caution.
Tracking the Evolution of Symptoms
Symptoms of a concussion are dynamic and can change significantly over the first few days of recovery. While some symptoms, like vomiting or initial confusion, may resolve quickly, others, like fatigue and irritability, may only appear 24 to 48 hours later. This is why the first two days after a head impact are considered the most critical monitoring period.
During this time, the person should be under the supervision of a responsible adult who can track whether symptoms are improving or worsening. Using a simple diary to record the severity of headaches or the frequency of dizzy spells can help healthcare professionals understand the recovery trajectory. Most minor concussions will see a steady improvement in all symptom categories within 7 to 10 days of the injury.
Differentiating Between Concussion and Emergency Red Flags
While most concussion symptoms are manageable with rest, it is vital to know which signs indicate a more serious traumatic brain injury. These “red flag” symptoms suggest that there may be bleeding or swelling inside the skull putting pressure on the brain tissue. If any of these signs appear, it moves the injury from a simple concussion to a medical emergency.
| Symptom Category | Typical Concussion (Monitor) | Emergency Red Flag (Call 999) |
| Consciousness | Brief or no loss of consciousness. | Prolonged or repeated loss of consciousness. |
| Headache | Mild to moderate, managed with rest. | Severe, worsening, or not helped by medicine. |
| Vomiting | Feeling sick or vomiting once. | Repeated or projectile vomiting. |
| Mental State | Slightly dazed or confused. | Increasing confusion, aggression, or fits. |
| Physical Signs | Dizziness or blurred vision. | Weakness in limbs, pupils of different sizes. |
Conclusion
The symptoms of a concussion are diverse, affecting a person’s physical health, mental clarity, and emotional stability. While a persistent headache and dizziness are the most common signs, cognitive “fogginess” and behavioural changes are equally important indicators of a brain injury. Most individuals will see their symptoms resolve within a short period through physical and mental rest. Vigilance during the first 48 hours remains the most important safety step for anyone who has sustained a head impact. If you experience severe, sudden, or worsening symptoms, call 999 immediately.
Can I have a concussion if I didn’t get knocked out?
Yes, the majority of people who sustain a concussion remain conscious throughout the entire event.
How long do concussion symptoms usually last?
Most symptoms resolve within 7 to 14 days, although children and teenagers may take slightly longer to recover fully.
Is it normal to feel depressed after a head injury?
Temporary changes in mood, including feeling sad or anxious, are common as the brain heals from the chemical disruption of a concussion.
Why do my symptoms get worse when I look at a screen?
Bright lights and fast-moving images force the brain to work harder, which can trigger headaches and nausea while the brain is still healing.
Can a concussion cause a fever?
A fever is not a typical symptom of a concussion; if a fever develops after a head injury, it should be assessed for other causes or complications.
What if my headache doesn’t go away after a week?
If symptoms like headaches persist for more than two weeks, you should seek medical advice to check for post-concussion syndrome.
Should I wake a concussed person every hour?
Current guidance suggests it is usually safe to let them sleep, but you should check on them every few hours to ensure they are breathing normally and can be woken.
Authority Snapshot (E-E-A-T Block)
This guide provides evidence-based information on the symptoms of head injuries and concussions according to UK medical standards. It has been reviewed by Dr. Stefan Petrov, a UK-trained physician with extensive experience in emergency care and general surgery. This article aims to provide clear, safe, and factual public health information in alignment with the guidelines set by the NHS and NICE.
