In older adults, the prevalence of anxiety disorders is higher among those with other health problems, and those in hospital and care settings. A primary depressive disorder should be excluded whenever an older person presents with anxiety symptoms for the first time, and comorbid anxiety often indicates a more severe presentation of depression. Around four in five patients have a comorbid physical disorder. Medical conditions can mimic symptoms of, predispose to, or even directly precipitate an anxiety disorder, and may colour its symptomatology or limit treatment options.