There are several possibilities for sudden memory loss: 1. Ischemic stroke, cerebral infarction with ischemic lesions located in the cerebral cortex or hippocampus or insula, and transient ischemic attack can lead to sudden memory loss in patients, mostly in middle-aged and elderly people over 50 years old, mostly with underlying diseases such as hypertension. Some patients with memory loss can relieve themselves, such as patients with transient ischemic attack, while patients with cerebral infarction need to improve their memory function through Patients with cerebral infarction need to be treated with intravenous thrombolysis, stenting for embolism, or antiplatelet and cerebrovascular dilation to improve memory function.2. Central nervous system infection, viral encephalitis is the most common central nervous system infection that causes sudden amnesia, and patients can have sudden amnesia after several days of fever, which can be accompanied by headache, vomiting, and psychiatric symptoms.3. Epilepsy, patients with complex partial seizures and generalized seizures can also have transient amnesia Symptoms.