Insomnia and sleep disturbances in the aged.
D000368:Aged; D004569:Electroencephalography; D006801:Humans; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis* / Q000523:psychology; D012894:Sleep Stages; D012893:Sleep Wake Disorders / Q000175:diagnosis* / Q000523:psychology; D012895:Sleep, REM