When someone you love has been in an accident, the most obvious injuries such as cuts, bruises, and broken bones are the ones that get immediate attention. Yet brain injuries can hide in plain sight. A sudden blow or jolt to the head may disturb normal brain function, and the warning signs often develop slowly. In this guide we explore the signs individuals may recognise early on, so they can secure the right medical treatment and, where negligence is involved, the compensation needed to fund recovery.