Final answer:
Pulmonary hypertension secondary to other conditions or medications is often caused by increased pressure in the pulmonary capillaries, as seen in heart failure or congenital heart defects like patent ductus arteriosus. These conditions can lead to pulmonary edema and require medical management or surgery to prevent serious complications.
Step-by-step explanation:
When pulmonary hypertension is secondary to other conditions or medications, it is often the consequence of increased hydrostatic pressure within the pulmonary capillaries. This can occur in cases such as heart failure, where the left ventricle fails to pump sufficient blood into the systemic circulation, leading to a backup of blood in the pulmonary circulation. The backed-up blood starts in the left atrium, then moves to the pulmonary veins, and finally into the pulmonary capillaries, causing the fluid to leak into lung tissues, a condition known as pulmonary edema.
Similarly, congenital heart defects like a patent ductus arteriosus can result in increased pulmonary pressure due to abnormal blood flow from the higher pressure aorta into the pulmonary trunk, complicating respiration. Treatment options for conditions that cause pulmonary hypertension vary from medications, lifestyle changes for managing hypertension, to surgical interventions in cases of congenital defects to prevent serious complications like congestive heart failure.