Sudden forgetfulness in the elderly may be caused by acute cerebrovascular disease such as cerebral infarction or cerebral hemorrhage if the symptoms do not subside. If the symptoms persist and do not subside, it may be caused by an acute cerebrovascular disease such as cerebral infarction or cerebral hemorrhage. If an elderly person suddenly forgets something, if the symptoms can be relieved for a while, it is considered to be a transient ischemic attack or early symptoms of dementia. If the elderly forgetfulness is caused by cerebrovascular disease, the lesion should be in the temporal lobe and near the hippocampus. If an elderly person has occasional forgetfulness, it may be caused by Alzheimer’s disease, and the patient may be in the early stages of Alzheimer’s disease, which is characterized by recent memory loss and should be treated early.