Aggression or hostility towards staff is difficult and distressing. Sometimes this is driven by substance abuse or may be criminal. In most cases, however it is a consequence of ill-health, or associated with the circumstances of hospitalisation. Emergency departments have their challenges, but the commonest location for reported aggression is geriatric and medical wards, the commonest underlying causes being delirium and dementia. Fortunately, the approach to prevention and management is similar across conditions. Firstly, we must understand why aggression arises: it is mostly an expression of distress or unmet need. Prevention comprises attempting to anticipate or meet these needs, through an attitude of respect, personalising management, and care, showing empathy, and using relationships to meet basic psychological needs. Physicians must identify and treat any underlying medical cause. Where situations are deteriorating, we need to know how to de-escalate, by minimising provocations, and though negotiation. In crisis situations, we need to know what is legal, and act swiftly and with confidence. Intervention is allowed when justified, necessary and proportionate to likely harm. This can include physical intervention, ideally after appropriate training, or using sedative drugs. Application on admission units, medical and geriatric wards is challenging but possible, requiring leadership, skills and resources.