Pulmonary hypertension is elevated blood pressure in the lungs.
This disorder of the circulation can be caused by any disease that blocks the flow of blood through the lungs. People who live for many years at high altitudes are especially susceptible to pulmonary hypertension, but almost any lung disease can lead to this condition. When no underlying cause can be found, the disease is called primary pulmonary hypertension. Whatever the cause, the main result is increased pressure within the pulmonary arteries, which carry blood from your heart to your lungs. In time this leads to thickening of the arteries and narrowing of the arterial passageways, which further obstruct the flow of blood.