Unsteady standing and swaying may be a posterior circulation transient ischemic attack, or it may be a cerebellar brainstem infarction, cerebellar brainstem hemorrhage or cerebellar brainstem tumor. The symptoms of posterior circulation transient ischemic attack are usually episodic in patients, the duration of most of them varies from 10-15 minutes, the symptoms are completely relieved within 24 hours, the cranial CT examination is normal, most of them occur in middle-aged and elderly people, and the patients may have hyperlipidemia, diabetes, hypertension and atherosclerosis. If the patient has cerebellar or brainstem infarction or cerebellar or brainstem hemorrhage, the symptoms are usually persistent and the patient may suddenly develop dizziness, nausea, vomiting, impaired balance and ataxia. Cerebellar and brainstem hemorrhage usually starts during activity, while cerebellar and brainstem infarction mostly starts in a quiet state, and cranial CT examination can make a clear diagnosis. Patients with cerebellar and brainstem tumors usually have a chronic onset, while patients may have headache, nausea, vomiting, and also dizziness, and cranial MRI can make a definite diagnosis.