The active ingredient in coffee is mainly caffeine, which has a certain excitatory effect on the central nervous system. Drinking coffee in large quantities for a long time may stimulate the nervous system, including the cerebellar area and the balance organs causing dizziness, blurred vision and other symptoms. A one-time excessive coffee consumption by people who have never drunk coffee may cause the vasoconstriction effect to be strengthened, and even cause the phenomenon of elevated blood pressure and increased heart rate, and also cause short-term dizziness, blurred vision, dizziness and headache, which is closely related to the effect of coffee. People who drink coffee for a long time will not appear obvious dizziness, the body has gradually adapted, if itself has high blood pressure, coronary heart disease, cerebrovascular disease of the population, is not suitable for long-term coffee consumption, there may be head discomfort.