Why does chronic left heart failure appear pulmonary congestion

Chronic left heart failure is caused by an

increase in the amount of blood in the pulmonary circulation, which makes the pulmonary vessels fill too much, beyond the normal range. Chronic left heart failure is caused by the inability of the heart to effectively transport blood to the body tissues due to left ventricular failure. After the disease, blood will accumulate in the left ventricle and flow back to the left atrium and pulmonary veins, increasing the pressure of pulmonary veins and pulmonary capillaries, making the amount of blood in the pulmonary circulation increase, exceeding the volume load of pulmonary vessels, and eventually causing pulmonary congestion.