Dizziness is caused by temporary ischemia and hypoxia of brain tissue. The causes of dizziness after running are mainly the following: 1. Low blood pressure, patients usually have no discomfort, but after strenuous exercise will lead to a transient increase in blood pressure, the symptoms of cerebral artery insufficiency, dizziness and other discomfort. When running for the first time is not recommended too fast, too hard, you can run for a short time or jogging, warm up before running, drink more water after running, and then fast running, if you have heart disease is not recommended to run.