Pulmonary hypertension begins when the arteries that carries blood from the lungs to heart are blocked, narrowed, or constricted, thus obstructing the blood flow from your heart and through your lungs. In turn, heart works harder to push blood beyond the blockages, resulting in increased blood pressure in the arteries and heart. Over time, the heart and heart muscles are weakened because it has to perform so many functions at one time. This condition can also lead to heart failure and eventual death.
