Four key factors can independently predispose individuals to delirium: vision impairments, severity of illness, cognitive impairment, and dehydration. Additional predisposing factors include advanced age, dementia, medical illnesses, infections, malnutrition, sensory impairment, surgery, and multiple medications or substances. The risk of delirium increases based on the number of predisposing factors and can be precipitated by physical restraints, malnutrition, catheters, multiple new medications, or medical complications. Certain genes may also increase vulnerability. The Confusion Assessment Method (CAM) and Memorial Delirium Assessment Scale (MDAS) are tools used to diagnose and assess the severity of delirium.