Subdural hematoma (SDH) is bleeding between the dura and the arachnoid. Symptoms depend on how fast blood accumulates, the size of the clot, and the patient’s age or brain atrophy. They may appear within minutes (acute), days (sub-acute) or weeks (chronic). HeadachePersistent, often severe and worsening; classically more noticeable on awakening. Nausea and vomitingRaised intracranial pressure triggers frequent vomiting with little relief. Altered consciousnessDrowsiness, lethargy, sudden confusion, or memory loss; a lucid interval may precede deterioration. Focal neurologyWeakness or numbness on the side opposite the bleed, slurred speech, unequal pupils, or vision changes. SeizuresFocal or generalised fits are common when... Learn more