Head injury and concussion: a case-based approach

The case: a fall and a bumped head

A woman slips on a wet floor and bangs the side of her head, briefly feeling dazed but not clearly knocked out. She gets up, feels shaken, and over the next hour develops a headache and feels a little sick. She did not vomit, can remember the fall, and is talking normally. This is a very common picture. Most such injuries are minor: the brain has been shaken but not seriously harmed. The clinician's task is to work out whether this is one of the many that will settle with simple care, or one of the few where something more serious is developing inside the skull. The way to do that is to look for specific warning signs and to watch how the person changes over the following hours.

What concussion actually is

Concussion is a temporary disturbance of how the brain works after a knock to the head, without any lasting structural damage that shows up on standard scans. It can cause headache, feeling dazed or foggy, dizziness, nausea, sensitivity to light or noise, difficulty concentrating, and feeling more tired or emotional than usual. Symptoms may start straight away or come on over a few hours. Importantly, concussion does not require being knocked out — many people are never unconscious. Most people recover fully within days to a couple of weeks with rest and a gradual return to normal activities. The key is that concussion is a diagnosis of a mild injury, made only once the more serious possibilities have been considered and warning signs are absent.

The red flags that mean urgent care

Certain features suggest bleeding or swelling inside the skull and mean someone needs urgent hospital assessment. Following UK (NICE) guidance, go to A&E or call 999 if there has been any loss of consciousness, vomiting more than once, a fit or seizure, increasing drowsiness or difficulty staying awake, confusion or odd behaviour, weakness, numbness, problems with speech, vision or balance, or a severe or worsening headache. Clear fluid or fresh blood leaking from the ears or nose, a black eye or bruising behind the ear with no obvious cause, or any deep wound or suspected skull fracture are also red flags. Head injuries caused by high-speed or high-force impacts, or in someone on blood-thinning medicines, need a lower threshold for going in.

How doctors assess a head injury

In hospital, assessment centres on the level of consciousness and how alert and oriented the person is, checked using a standard scale, together with the pupils, movement, and the story of what happened. Clinicians use agreed criteria to decide who needs a CT scan of the head, which is the test that shows bleeding or a fracture. Not everyone needs a scan; the criteria are designed to pick out those at real risk while sparing others unnecessary radiation. People who are on blood-thinning medicines are looked at especially carefully, because even a modest injury can bleed. Someone who is well but has one or two lower-risk features may be observed for a period rather than scanned immediately, with staff watching for any change.

Recovery, safety-netting and when to worry later

For a minor head injury like our patient's, the plan is usually simple: rest, ordinary pain relief such as paracetamol, and a responsible adult to keep an eye on the person for the next day or so. This safety-netting is important, because occasionally problems develop hours after the injury. The person, or those around them, should seek urgent help if any red flag appears — worsening drowsiness, repeated vomiting, a fit, confusion, weakness, or fluid from the ears or nose. Concussion symptoms such as headache and poor concentration can linger for a week or two; a gradual return to work, screens, sport and driving is sensible, guided by symptoms. If recovery stalls or symptoms persist, it is worth seeing a GP for further advice.