Minor head injury
GCS 15 and well? Use the NICE criteria to decide on CT, and send home only with a responsible adult and clear warning signs.
A 30-year-old man fell off his motorbike without a helmet. He was briefly knocked out and is now GCS 15 with a headache. He vomited once. He takes no medicines.
A 76-year-old woman on warfarin tripped and bumped her forehead. She is GCS 15 and has no symptoms.
A 22-year-old was hit on the side of the head, was "fine" for an hour, then became drowsy.
Who needs a CT, how urgently, and who can go home?
- ABCDE with the cervical spineAssume a neck injury until cleared.
- GCS, pupils, limb powerRecord and repeat.
- Check anticoagulants and antiplateletsWarfarin, DOAC, clopidogrel.
- CT within 1 hour ifGCS under 13 initially, GCS under 15 at 2 hours, open or depressed fracture, basal skull fracture signs, seizure, focal deficit, vomiting more than once.
- CT within 8 hours ifLost consciousness or amnesia with age 65 or more, bleeding tendency, dangerous mechanism, or over 30 minutes of retrograde amnesia.
- On anticoagulantsCT within 8 hours even without other features.
- HomeWith a responsible adult and written head injury advice.
- GCS falling by 2 or more
- Unequal pupils
- New weakness
- Seizure
- Severe or worsening headache, repeated vomiting
- Anticoagulated with any intracranial bleed
- Extradural haematoma (lucid interval)
- Subdural in the elderly or alcohol users
- Basal skull fracture
- Neck injury
- Non-accidental injury in children
- Hypoglycaemia or intoxication blamed for low GCS
| Mild | GCS 13–15 |
| Moderate | GCS 9–12 |
| Severe | GCS 8 or less (airway protection) |
| GCS 15 at 2 hours | Needed before discharge |
| Dangerous mechanism | Pedestrian or cyclist hit by a vehicle, ejection, fall from over 1 m or 5 stairs |
| Observation | GCS every 30 minutes until 15, then hourly and less often per local protocol |
Check every dose against a current drug reference and your hospital protocol.
On this page
Assessment
- Mechanism: speed, height, helmet, ejection.
- Loss of consciousness, amnesia (before and after), vomiting, headache, seizure.
- Medicines: anticoagulants, antiplatelets.
- Alcohol or drugs: never assume low GCS is just alcohol.
- Examination: GCS, pupils, limbs, scalp, signs of basal skull fracture, neck.
- Bruising around both eyes (raccoon eyes).
- Bruising behind the ear (Battle's sign).
- Blood or clear fluid from the ear or nose (CSF).
- Blood behind the eardrum (haemotympanum).
Who needs a CT head? (adults)
CT within 1 hour
CT within 8 hours
CT within 8 hours
- No CT needed
- discharge with advice
Types of bleed
| Bleed | Typical story | CT |
|---|---|---|
| Extradural | Blow to the temple, middle meningeal artery, lucid interval then rapid decline | Lens-shaped (biconvex), doesn't cross sutures |
| Acute subdural | Elderly, alcohol, falls; bridging veins | Crescent-shaped, crosses sutures |
| Chronic subdural | Weeks after a minor fall, confusion, headache, fluctuating GCS | Darker crescent |
| Subarachnoid (traumatic) | With other injuries | Blood in the sulci |
| Contusion | Coup and contrecoup | Patchy bleeding in the brain |
Discharge
Safe if:
- GCS 15, no CT indication or a normal CT.
- A responsible adult can stay with them for 24 hours.
- Written advice given.
- Drowsiness or hard to wake.
- Confusion, slurred speech, weakness.
- Repeated vomiting.
- Seizure.
- Severe or worsening headache.
- Clear fluid from the nose or ears.
Concussion: headache, poor concentration and tiredness can last days to weeks. Rest from screens and sport for a short period, then return gradually. No contact sport until symptoms have gone.
Children
- Use child-specific CT rules (different thresholds).
- Under 1 year: any bruise, swelling or laceration over 5 cm on the head counts.
- Always consider non-accidental injury: inconsistent story, delay, other bruises.
Treatment
Avoid sedating analgesia that clouds the GCS. Reversal of anticoagulants for an intracranial bleed is a senior decision: see warfarin.
Common mistakes
- Blaming low GCS on alcohol.
- Discharging an anticoagulated patient without a CT.
- Forgetting the neck.
- Missing the lucid interval of an extradural.
- Sending home a patient with nobody to watch them.
Frequently asked questions
When does a head injury need a CT scan within 1 hour?
GCS under 13 at first, GCS under 15 at 2 hours, a suspected open, depressed or basal skull fracture, a seizure, a focal deficit or more than one vomit.
Does a patient on warfarin with a minor head injury need a CT?
Yes, within 8 hours, even without other symptoms.
What is a lucid interval?
A period of normal consciousness after a head injury before deterioration, classically with an extradural haematoma.
What are the signs of a basal skull fracture?
Raccoon eyes, Battle's sign, CSF leaking from the nose or ear and blood behind the eardrum.
Test yourself
Exam-style questions on this guide, from our two question banks. Choose an answer to see why each option is right or wrong.
1. A 22-year-old with a head injury has GCS 15 and vomited once. He is not on anticoagulants. Does he need a CT?
Answer: No CT. One vomit alone doesn't meet NICE CT criteria; give written advice.
- MRI: No.
- CT within 8 hours: Not for this alone.
- CT within 1 hour: Needs more than one vomit.
- Skull X-ray: Not used.
2. Which feature needs a CT head within 1 hour?
Answer: Repeated vomiting. High-risk features include GCS below 15 at 2 hours, skull fracture signs, seizure, focal deficit and repeated vomiting.
- Age 40: No.
- Mild headache: No.
- Scalp laceration: No.
- Being drunk alone: Not a criterion by itself.
3. What advice is given after concussion?
Answer: Gradual return to activity. Return urgently with worsening symptoms.
- Return to sport tomorrow: No.
- Avoid sleeping: Not needed.
- Drive home immediately: No.
- Strict bed rest for 2 weeks: Not recommended.
4. After a head injury, a man has bilateral periorbital bruising sparing the tarsal plates, bruising behind the ear and clear fluid from the nose. What is the diagnosis?
Answer: Base of skull fracture. Signs of base of skull fracture: periorbital ecchymoses (‘raccoon eyes’), Battle sign (mastoid bruising — appears after 24–48 h), CSF rhinorrhoea/otorrhoea, haemotympanum, cranial nerve palsies (VII, VIII). Needs CT head; avoid nasal tubes; watch for meningitis (pneumococcal vaccination for persistent leaks; prophylactic antibiotics not routine). Most CSF leaks resolve spontaneously.
- Le Fort I fracture: Le Fort I involves the palate and maxilla.
- Orbital floor blowout: An orbital blowout causes diplopia and cheek numbness.
- Extradural haematoma: Extradural haematoma is an intracranial bleed.
5. An 80-year-old on aspirin with alcohol excess has 3 weeks of fluctuating confusion, headache and mild left hemiparesis after a minor fall. CT shows a crescent-shaped hypodense collection. What is the treatment?
Answer: Burr-hole drainage. Chronic subdural haematoma: elderly, alcohol, anticoagulants/antiplatelets, brain atrophy; torn bridging veins after minor trauma; weeks later — fluctuating confusion, headache, focal signs. CT: crescentic, hypodense (or mixed), crossing suture lines. Symptomatic → burr-hole drainage (± drain); reverse/stop antithrombotics. Recurrence ~10–20%.
- Craniotomy for all: Burr holes usually suffice.
- Observation only with deficit: She is symptomatic.
- Thrombolysis: Thrombolysis is contraindicated.
6. An elderly alcoholic on warfarin has fluctuating confusion over two weeks after a minor fall. CT shows a crescent-shaped collection crossing suture lines. Which vessels bled?
Answer: Bridging veins (subdural haematoma). Subdural haematoma: tearing of bridging veins between cortex and dural sinuses; crescent-shaped, crosses sutures; risk in elderly, alcoholics (brain atrophy) and anticoagulated patients; may be chronic with fluctuating consciousness. Extradural: middle meningeal artery after temporal fracture, lens-shaped, does not cross sutures, lucid interval.
- Middle meningeal artery: Extradural: lens-shaped.
- Berry aneurysm of the circle of Willis: Subarachnoid haemorrhage.
- Lenticulostriate arteries: Hypertensive intracerebral bleed.
- Superior sagittal sinus: Not the usual source.
7. A man with a large head injury develops hypertension, bradycardia and irregular breathing. What does this triad indicate?
Answer: Cushing reflex. When ICP rises toward MAP, brainstem ischaemia triggers a sympathetic surge raising blood pressure to maintain cerebral perfusion (CPP = MAP − ICP); baroreceptors then cause reflex bradycardia, and brainstem compression disturbs breathing. This Cushing triad is a late, ominous sign requiring urgent measures to lower ICP.
- Neurogenic shock: Hypotension and bradycardia after cord injury.
- Hypovolaemic shock: Tachycardia, hypotension.
- Septic shock: Warm periphery, hypotension.
- Spinal shock: Loss of reflexes below a cord lesion.
References and dose sources
- NICE NG232 — Head injury: assessment and early management
- Paracetamol dosing: Drugs.com: Acetaminophen (paracetamol) dosage (see also our paracetamol dose page)
- Ondansetron dosing: Drugs.com: Ondansetron dosage (see also our ondansetron dose page)
International guidance is linked where it reflects good practice. Where your hospital’s protocol differs, follow your hospital.