Pathological changes of the heart refer to the dysfunction of the heart and its functions to govern the mind and blood vessels, clinically marked by palpitation, heart pain, dysphoria, insomnia, dreaminess, amnesia, derangement, knotted pulse, slow regular intermittent pulse or rapid irregular intermittent pulse. Since the heart opens to the tongue, so some of the tongue disorders, such as tongue pain and tongue sore, which are also related to the heart.
 
The heart disease is either asthenic or sthenic. Asthenic heart disease is usually due to excessive anxiety, congenital defects, asthenia of visceral qi in senility or impairment of the heart by prolonged illness which leads to asthenia of heart qi, asthenia of heart blood, asthenia of heart yin and sudden loss of heart yang. Sthenic heart disease is due to phlegm retention, fire disturbance, cold coagulation, qi stagnation and blood stasis which lead to obstruction of heart vessels, hyperactivity of heart fire, and confusion of heart by phlegm and phlegmatic fire disturbing the heart, etc.