Chronic subdural haematoma (cSDH) is an encapsulated collection of liquefied blood over the brain surface, seen mostly in older people and often after a minor head injury. It persists because a fragile, inflamed outer membrane, supplied by the middle meningeal artery (MMA), keeps bleeding into the cavity. It presents with headache, cognitive or gait decline or a focal deficit, and non-contrast CT makes the diagnosis and guides the choice of treatment. Symptomatic collections with mass effect are evacuated through a burr hole or twist drill and drained, while mild collections may be observed. Recurrence after evacuation is the main problem. MMA embolisation is used as an adjunct to evacuation to prevent it, and in selected patients instead of surgery, where societies differ. Steroids are not given routinely.