Insufficient blood supply to the brain at the age of 20 is mainly caused by physiological reasons: 1, such as long-term mental stress, excessive tension, sleep disorders, irregular life may cause, should relax, reduce stress, appropriate to participate in some exercise, improve sleep, develop good habits, to ensure adequate sleep time may improve. 2, may also be due to long-term low desk work, play cell phones, look at the computer, and should develop good habits, reduce the time to play mobile phones, look at the computer, appropriate rest at work. 3, may also be due to long-term smoking, smoking patients can cause damage to the intima, can make the blood in the formation of components gathered in the blood vessel wall, and lead to stiffness, lumen narrowing, can cause cerebral blood supply deficiency. 4, if the patient has a vascular malformation, such as smoke disease, may also cause 5. Patients with cervical spondylosis may also be caused.