As mentioned earlier, the autonomic nervous system is also part of "liver qi" and "internal wind." In particular, the sympathetic nervous system is positive and yang in nature. When its regulation becomes excessive or overly forceful, it can lead to "ascendant hyperactivity of liver yang." The main symptoms include dizziness, headache, facial flushing, blurred vision, and tinnitus. If the sympathetic nervous system is overactive, arteries (excluding skeletal muscles) will constrict, the heart will contract more forcefully, heart rate will increase, and skeletal muscle tension will rise, leading to elevated blood pressure. Increased intracranial pressure can cause headaches, dizziness, and tinnitus. The blood vessels in the eyes, such as those of blackend swallowwort root, may become red due to congestion. The increased pressure in blood vessels and skeletal muscles causes blood to rush to the head, creating a sensation of "rising to the head," hence the term "ascendant hyperactivity of liver yang."