In old age, cognitive functions decline in comparison to performance earlier in life. Subjective memory complaints often cause anxiety. Patient and informant history taking, along with simple additional cognitive tests are usually sufficient to reassure patients or to initiate further diagnostic work-up. Differential diagnoses include depression, delirium, other psychiatric or neurological disorders, metabolic causes, intoxications or side effects of drugs. Physical examination and laboratory tests generally have limited added value. Main reasons for referral are a suspected treatable cause for cognitive decline (e.g. delirium), focal neurological deficit (e.g. stroke), suspected dementia under the age of 65-70 years, additional complex somatic or psychiatric disorders or further work-up in non-native speaking people.