Head Injuries: Warning Signs and When A&E Is Essential

Why head injuries are different

Head injuries range from minor bumps that need nothing more than rest to life-threatening bleeds inside the skull that require emergency surgery. The challenge is that serious head injuries do not always look dramatic at first — a person can walk and talk after a significant blow and then deteriorate hours later. This guide explains the warning signs, when to go straight to A&E, when to call 999, and when it is safe to manage at home.

Types of head injury

Concussion

A concussion is a temporary disturbance of brain function caused by a blow, jolt or shake. The person may feel dazed, confused, have a headache, feel sick, have blurred vision or have trouble remembering what happened. Most concussions resolve within days to weeks, but they need proper monitoring.

Scalp wound

The scalp has a rich blood supply, so even small cuts can bleed heavily. A bleeding scalp wound looks alarming but is usually not dangerous in itself. Apply firm pressure with a clean cloth for at least 10 minutes. The wound may need stitches or glue — a UTC can handle this.

Skull fracture

A crack in the skull bone. Signs include swelling or a dent over the injury site, bruising around the eyes or behind the ears (may develop hours later), and clear fluid leaking from the nose or ears. Skull fractures need A&E assessment.

Intracranial haemorrhage

Bleeding inside the skull, either on the surface of the brain (subdural or extradural haematoma) or within the brain tissue itself. This is the most dangerous consequence of a head injury. It can develop rapidly (extradural) or slowly over days to weeks (subdural). Older adults and people taking blood-thinning medication are at particularly high risk of subdural haematomas — see our elderly A&E guide.

When to call 999

Call 999 immediately if the person:

• Was knocked unconscious, even briefly
• Is not fully alert — confused, drowsy, difficult to wake, or not responding normally
• Is having a seizure (fit)
• Has clear fluid or blood leaking from the nose or ear
• Has a visible skull deformity or a large, boggy swelling
• Has weakness or numbness in an arm or leg
• Has difficulty speaking or understanding speech
• Has had more than one episode of vomiting since the injury
• Was injured by a high-energy mechanism: road traffic collision, fall from height (more than twice their own height), being hit by a thrown or swung object at speed

While waiting for the ambulance, if the person is unconscious but breathing, place them in the recovery position. Do not move them if you suspect a spinal injury (neck or back pain, tingling in limbs, mechanism suggesting spinal damage).

When to go to A&E

Go to A&E (an ambulance is not usually needed, but do not let the person drive) if:

• The person lost consciousness at any point, even momentarily
• They cannot remember what happened (amnesia for the event or the period before it)
• They have a persistent headache that is not improving with paracetamol
• They have vomited once since the injury
• They are on blood-thinning medication (warfarin, apixaban, rivarelbanan, clopidogrel, aspirin) — even a minor head injury carries significant risk when anticoagulated
• They are over 65 — lower threshold for serious injury
• They have had previous brain surgery or a known condition that increases bleeding risk
• The mechanism was significant — a fall from standing height onto a hard surface in an older adult, or any blow to the head involving a weapon or impact at speed
• The injury is in a baby or young child — our children's guide covers additional red flags

Check live A&E wait times to choose the quickest department, but do not delay attending if the person has any of the above signs.

When it is safe to stay at home

A head injury can be managed at home if all of the following are true:

• The person did not lose consciousness at any point
• They can remember the injury clearly
• They are fully alert, oriented and behaving normally
• They have, at most, a mild headache that improves with paracetamol
• They have not vomited
• They are not on blood-thinning medication
• The mechanism was minor — a bump against a cupboard, a minor slip without significant impact

Home monitoring — the next 24 hours

Even with a minor head injury, monitor the person for the next 24 hours. Wake them every 2–3 hours overnight to check they are responsive and orientated. Go to A&E if any of the following develop:

• Increasing drowsiness or difficulty waking
• Confusion or unusual behaviour
• Severe or worsening headache
• Vomiting
• Seizure
• Weakness in an arm or leg
• Vision changes — double vision, blurred vision
• Clear fluid from nose or ear
• Difficulty speaking or understanding speech
• Unusual irritability (especially in children)

Head injuries in children

Children bump their heads constantly — it is a normal part of childhood. Most head bumps in children are minor and need nothing more than a cuddle, an ice pack and observation. However, children under one year are at higher risk because their skulls are thinner and they cannot tell you how they feel.

Take a child to A&E if:

• They were knocked unconscious, even briefly
• They are drowsy, difficult to wake, or not feeding normally (babies)
• They have vomited more than once
• They have a large, boggy swelling on the head (not just a bump)
• They are inconsolable and not responding to normal comforting
• The fall was from more than their own height onto a hard surface
• They are under 12 months with any head injury beyond a very minor bump

For more on children and A&E, see our parent's guide.

Head injuries in older adults

Older adults are at significantly higher risk from head injuries because:

• Blood-thinning medication is more common — and dramatically increases bleeding risk inside the skull
• Subdural haematomas can develop slowly over days to weeks — a minor bump today can cause progressive confusion and weakness two weeks later
• Falls are more frequent and recovery is slower
• Communication of symptoms may be complicated by existing cognitive impairment

Any older adult on blood thinners who has a head injury should attend A&E, regardless of how minor the impact seems. Our elderly A&E guide covers additional considerations.

At the hospital

If you attend A&E with a head injury, the process typically follows these steps:

1. Triage — assessment of consciousness level, vital signs and mechanism of injury
2. Clinical assessment — neurological examination including pupil response, limb strength, coordination and cognitive function
3. CT scan — if clinical criteria are met (loss of consciousness, amnesia, vomiting, anticoagulation, high-mechanism injury, abnormal neurological findings)
4. Observation — if the CT is normal, you may be observed for a period before discharge
5. Admission — if the CT shows a bleed or fracture, you will be admitted, potentially to a neurosurgical unit

Recovery from concussion

Most concussions resolve within 7–10 days. During recovery:

• Rest from physical activity for at least 48 hours
• Avoid screens if they worsen headache
• Do not return to contact sports until fully recovered — a second concussion before the first has healed is extremely dangerous
• Avoid alcohol
• Paracetamol for headache (avoid ibuprofen in the first 24 hours as it can increase bleeding risk)
• Gradually return to normal activities as symptoms allow

If symptoms persist beyond two weeks, see your GP for a post-concussion assessment.

Supporting someone with a head injury at home

If A&E discharges the patient with a head-injury observation sheet, take it seriously. For the first 24 hours, someone should stay with the injured person and check on them regularly — including waking them every two to three hours during the night to confirm they respond normally. Keep the environment calm and quiet, avoid alcohol, and do not give sedating medication unless prescribed. Make sure the injured person avoids driving, operating machinery or making important decisions for at least 48 hours after the injury, as judgment and reaction times may be impaired even when the person feels fine.

Children with head injuries need especially close monitoring because they may not be able to describe symptoms like blurred vision, dizziness or nausea. Watch for changes in behaviour — unusual irritability, drowsiness, loss of interest in food or play — and return to A&E immediately if anything concerns you. Our children's A&E guide covers paediatric red flags in more detail.

Bottom line

Head injuries need careful assessment because serious complications can develop hours after an apparently minor bump. When in doubt, attend A&E — particularly if the person lost consciousness, cannot remember the injury, is on blood thinners, or is very young or elderly. For clearly minor bumps with no red flags, monitor at home for 24 hours and attend immediately if symptoms develop. Our when to call 999 guide covers the situations where an ambulance is essential.