In a primary care setting, differentiating between a concussion and more serious head injuries primarily involves identifying specific risk factors that necessitate immediate referral to a hospital emergency department NICE NG232,NICE CKS. If any of the following risk factors are present, the person should be referred to a hospital emergency department, using the ambulance service if necessary:
- Glasgow Coma Scale (GCS) score of less than 15 on initial assessment NICE NG232,NICE CKS.
- Any loss of consciousness due to the injury NICE NG232,NICE CKS.
- Any focal neurological deficit since the injury NICE NG232,NICE CKS.
- Any suspicion of a complex skull fracture or penetrating head injury NICE NG232,NICE CKS.
- Amnesia for events before or after the injury (note: assessing amnesia may not be possible in preverbal children or those under 5) NICE NG232,NICE CKS.
- A persistent headache since the injury NICE NG232,NICE CKS.
- Any vomiting episodes since the injury (clinical judgement is used for children 12 years or under regarding the cause of vomiting and need for referral) NICE NG232,NICE CKS.
- Any seizure since the injury NICE NG232.
- Any previous brain surgery NICE NG232,NICE CKS.
- A high-energy head injury (e.g., fall from >1m or 5 stairs, high-speed motor vehicle collision, diving accident) NICE NG232,NICE CKS.
- Any history of bleeding or clotting disorders NICE NG232,NICE CKS.
- Current anticoagulant or antiplatelet treatment (except aspirin monotherapy) NICE NG232,NICE CKS.
- Current drug or alcohol intoxication NICE NG232,NICE CKS.
- Any safeguarding concerns (e.g., possible non-accidental injury or a vulnerable person is affected) NICE NG232,NICE CKS.
- Irritability or altered behaviour, particularly in babies and children under 5 NICE NG232,NICE CKS.
- Continuing concern by the professional about the diagnosis NICE NG232,NICE CKS.
- Signs of a suspected basal skull fracture, such as clear fluid leaking from the ear(s) or nose, periorbital haematoma(s) without associated eye damage, bleeding from one or both ears, blood behind the eardrum (haemotympanum), new deafness, or Battle's sign (bruising behind the ear) NICE CKS.
- Suspected cervical spine injury, indicated by neck pain or tenderness, or an inability to rotate the neck 45 degrees to the left and right NICE CKS.
If none of these risk factors are present, the person is considered at low risk of an intracranial complication or cervical spine injury NICE CKS. In such cases, advise that a responsible adult should stay with the person for the first 24 hours after the injury and remain alert for worrying signs and symptoms that indicate the need for urgent medical review NICE CKS. Symptoms such as headache, dizziness, nausea, and cognitive difficulties (often described as 'brain fog') can be part of 'post-concussion syndrome', which can occur even with mild head injuries NICE NG232.