If you feel black in front of your eyes when you stand up after sitting for a long time, consider the occurrence of postural hypotension. Postural hypotension refers to a significant drop in blood pressure, often exceeding 20 mmHg, when the patient changes position, such as from sitting or lying to upright position, and because of low postural hypotension, the patient can suffer from severe cerebral blood supply deficiency, which can cause blackness and even syncope. For patients with postural hypotension, it is important to move slowly when changing position in general, and in severe cases, patients can also be given elastic stockings and elastic pants to prevent it. For diseases that are likely to cause postural hypotension, such as cardiovascular diseases and diabetes, active treatment should be given. It is also necessary to actively engage in physical exercise in order to enhance one’s physical fitness.