Dizziness in the elderly is mostly related to atherosclerosis and inadequate blood supply to the brain. There are many causes of cerebral insufficiency, if dizziness is more obvious in the afternoon, the possible causes are as follows: 1, high blood pressure can cause cerebrovascular tension to increase, causing cerebral insufficiency, resulting in dizziness; 2, if patients with hypertension do not take medication according to the peak blood pressure time, blood pressure fluctuations may occur. If the blood pressure is relatively stable in the morning after taking the medication in the morning and is not adjusted in time in the afternoon, high blood pressure can cause dizziness; 3. Related to the heart and cerebrovascular, it is recommended that further electrocardiogram examination can be performed to observe whether the blood supply to the heart muscle is poor, especially if there are signs of cardiac arrhythmia. In addition, head CT examination or MRI of the brain is needed to observe the presence of cerebral ischemic foci, especially the manifestation of cerebral infarction; 4. Also, attention should be paid to the detection of factors affecting atherosclerosis, such as blood sugar and blood lipids, because atherosclerosis often causes cardiovascular and cerebrovascular diseases, which can also cause dizziness. Therefore, in addition to blood pressure, the elderly need to pay attention to the presence of other cardiovascular and cerebrovascular diseases in addition to dizziness.