| Image = | Caption = | DiseasesDB = 29284 | ICD10 = | ICD9 = | ICDO = | OMIM = | MedlinePlus = | eMedicineSubj = med | eMedicineTopic = 3006 | MeshID = D003693 |}}Delirium is an acute and relatively sudden (developing over hours to days) decline in attention-focus, perception, and cognition. In medical usage it is not synonymous with drowsiness, and may occur without it. It is commonly associated with a disturbance of con