The tilt test, also known as the upright tilt test, refers to the fact that when a normal person changes from a prone to an upright position, it results in a decrease in cardiac output and a decrease in arterial pressure. Sympathetic nerves are excited, so there can be a mild increase in heart rate, low systolic blood pressure, and an increase in diastolic blood pressure. However, if there is an abnormal tilt test, in which the upright postural tachycardia syndrome is characterized by a marked increase in heart rate, there will be a syncopal precursor of panic attacks and fatigue. There is also a marked decrease in systolic or diastolic blood pressure. Vasovagal syncope and autonomic dysfunction are characterized by a drop in blood pressure and bradycardia. The main significance of the tilt test is that it is a very important tool for identifying syncope. It can be used to identify vasovagal, cardioinhibitory and mixed types of syncope.