Why to stand long meeting giddy, before the eye blackens

After standing for a long time, the patient's eyes are dark. It is considered that the patient's cerebral ischemia and lack of blood supply to the brain caused by hypoxia will cause the symptoms of dark eyes. It is also considered that the patient has hypoglycemia, myocardial ischemia and other reasons, and the symptoms of dark eyes will also occur. It is recommended that the patient go to the hospital for examination and treatment in time.