It is mostly caused by blood failing to nourish the liver. The main symptoms include vertigo, headache, blurred vision, dry eyes, night blindness, amenorrhea, and scanty menstruation. Liver yin deficiency often leads to ascendant hyperactivity of liver yang, such as elevated blood pressure, deafness, tinnitus, facial heat, numbness and tremor of the limbs, dysphoria, and insomnia. It is commonly seen in hypertension, neurosis, eye diseases, and menstrual disorders. See the entry on "ascendant hyperactivity of liver yang."