Age-associated memory dysfunction is common, and delirium may occur, especially in response to illness or stress. Prevention of delirium is possible with a proactive consultation intervention, which can reduce the incidence of delirium by about 40 to 50%.

Sleep cycle disturbances are increasingly important with advancing age, and sleep-disordered breathing associated with sleep apnea seems to rise in prevalence with advancing age. Anatomic changes, such as tissue laxity and diseases of the nose and sinuses, may contribute to sleep-disordered breathing. Sleep apnea may have a neurologic basis either in the sleep cycling center, leading to central sleep apnea, or in neurologic control of pharyngeal tissues.