Primary pulmonary hypertension is an increase in the blood pressure in the pulmonary artery, caused by a rare lung disorder. The effects of primary pulmonary hypertension, while often mostly genetic, can be aggravated by poor diet or lack of proper exercise. (The pulmonary artery is the blood vessel that distributes the blood from the right side of the heart to the lungs. This distribution of blood is known as pulmonary circulation.)

Primary pulmonary hypertension results from stiffening or tightening of the blood vessels that supply blood to the lungs. As a result of this, the right ventricle has to work harder to pump the blood forward. This stress on the heart enlarges and thickens the right ventricle and increases the blood pressure. Primary pulmonary hypertension occurs without any underlying heart or lung disease.

Symptoms of primary pulmonary hypertension include chest pain, especially during physical exercise, progressive weakness, shortage of breath, dizziness, fainting, fatigue, coughing up blood, swollen ankles and legs. More severe symptoms include failure to do minimal activities; it may result in the disease progressing to an advanced stage.

Causes of primary pulmonary hypertension are as yet unidentified and are rarely discovered during a routine medical checkup. The tests for diagnosis of primary pulmonary hypertension include an electrocardiogram (ECG), chest X-ray, ultrasound of the heart, nuclear lung scan, scan of chest, right-heart cardiac catheterization and pulmonary arteriogram. Once diagnosed, a specific course of treatment is advised by the doctors, depending upon the patient's age, overall heath, extent of the disease and tolerance to various medications and therapies.