A carotid resistance index of 0.74 is a normal value. The carotid resistance index is the ratio of the difference between the maximal and diastolic blood flow velocities measured in Doppler sound spectroscopy to the maximal blood flow velocity. Normal values are around 0.7 for the common carotid artery; 0.59 for the internal carotid artery; and 0.74 for the external carotid artery. Overall, normal values range from 0.55 to 0.75. When the index is greater than 0.75, it indicates that there is obstruction in the carotid artery vessels, which is mostly caused by decreased vascular compliance, atherosclerosis, carotid arterial n-vein plaques, etc., and if the condition further deepens it can lead to cerebral infarction or cerebral hemorrhage and other diseases. When the resistance index of the strength artery is greater than normal, patients should consult a doctor in time. Usually, we should also pay attention to the regulation of life and diet, eat more low-salt, low-fat, low-cholesterol food.