Constitutional Yin deficiency or prolonged liver-Qi stagnation turns to fire, which takes from the Yin-fluid in the body, so the insufficient Yin leads to the flaring up of fire and the floating of the imbalanced Yang. Such manifestations would take place as the consequence: palpitation, insomnia, dizziness, tinnitus, irritability, hot ...
Excessive thinking and worrying could over-exert the heart and spleen, leading to the insufficiency of both Qi and blood, so the heart is malnourished and the mind is disturbed, resulting in the waning of heart Qi and the declining of courageousness.