this is yin deficiency of the heart and kidneys. the heart governs the blood and stores the spirit, and its fire normally descends to meet with the kidneys. the kidneys store the essence and will, and kidney water normally rises to meet with the heart. when the heart and kidneys communicate harmoniously, fire and water balance each other, and the essence and heart are sufficient. under such circumstances, the spirit and will are calm and settled.

excessive thinking or deliberation injures the heart and kidneys, which depletes the blood and essence. deficient heart blood deprives the heart of nourishment, which causes palpitations with anxiety and forgetfulness. the depletion of blood and essence leads to fire from deficiency, which ascends to the heart and causes irritability, insomnia with very restless sleep, and an inability to think or concentrate for even short periods of time. night sweats and nocturnal emissions occur when the spirit rushes upward and the essence is lost downward.

disorders of the heart are manifested in the tongue; heart fire may therefore manifest as sores in the mouth and tongue. dry stools, a red tongue with little coating, and a thin, rapid pulse are common signs of yin and blood deficiency. the irritability, restlessness, and insomnia prevent the patient from getting enough sleep, which over time leads to fatigue.