Summary Managing patients with minor head injury with a simple blood test - secondary publication Ugeskr Læger 2009;171(12):978-981 The risk of acute intracranial complications after minor head injury (MHI) is low. Despite this, computed tomography (CT) is generally recommended with clinical observation as a secondary option. Both options have disadvantages. Clinical studies have shown the potential advantages of using the biomarker S100B. The specificity of S100B is low, but a high sensitivity for brain damage results in a clinically useful, high negative predictive value (NPV). Integration of S100B into existing management routines can reduce the need for CT scans or admission by over 30%.