Pulmonary hypertension is one of the major pulmonary vascular diseases. It is defined as an increase in pressure within the pulmonary arterial system above normal limits. The condition may be primary (a rare disorder with no other disease present) or secondary (see Etiology below).

There are a number of causes of secondary pulmonary hypertension. The causes include: an increase in red cell mass (blood viscosity); mitral stenosis; pulmonary embolism; and congenital heart disease. Chronic pulmonary hypertension causes right ventricular failure. Other factors that may be a cause of secondary pulmonary hypertension are: hypoxia, sickle cell anemia, chronic obstructive pulmonary disease (COPD), and left ventricular failure. These causes must be excluded for the disease to be termed primary.

The clinical symptoms in both types of the disease (primary and secondary) are similar. Symptoms of early, secondary pulmonary hypertension may be disguised by the disease causing the hypertension. Initially, dyspnea occurs with walking or exertion or both. Later dyspnea occurs when the patient is at rest. Dull chest pain, behind the sternum, resembling angina, may be present. Fainting (syncope) and fatigue with exertion occur. In advanced cases, cor pulmonale symptoms of enlarged liver, ascites, distended neck veins, wheezing, and chronic productive cough are seen.

Laboratory tests on the blood may show polycythemia (increase in red blood cells). Electrocardiograph (EKG) changes will demonstrate right ventricular hypertrophy and atrial enlargement. Other tests include: echocardiography, doppler ultrasonography, chest x-ray, ventilation/perfusion lung scanning, computed tomography (CT) scan, magnetic resonance imaging (MRI), cardiac catheterization, pulmonary angiography and, occasionally, a lung biopsy.

See residuals below for treatment of primary pulmonary hypertension. Secondary pulmonary hypertension treatment is aimed at the underlying cause. In general, these therapies include: frequent phlebotomy in cases of polycythemia vera; correction of acid-base imbalance; supplemental oxygen usage with COPD; inhalation of nitrous oxide to lower pulmonary artery pressure; anticoagulant use to combat embolism; and a surgical inferior vena cava interruption done to prevent recurrent life-threatening pulmonary emboli. In addition, bronchodilators, antibiotics for infection, and cardiopulmonary transplantation is used for cases of mitral stenosis and congenital heart disease.

The prognosis is poor for persons with primary pulmonary hypertension due to progressive right heart failure. Death usually occurs in 2 to 8 years unless lung transplantation or heart-lung transplantation takes place. There is a 49% two-year survival rate after transplantation. The prognosis is favorable in secondary pulmonary hypertension if the condition is detected early and the causes reversed.

• May be entitled to special monthly compensation where the Veteran has a single service-connected disability rated as 100% with additional service-connected disability or disabilities independently ratable at 60% or more, which are separate and distinct from the 100% service-connected disability and involves different anatomical segments or bodily systems. See  38 CFR 3.350(i)(1) – Special Monthly Compensation (SMC).

• Evaluate other residuals following pulmonary embolism under the most appropriate diagnostic code, such as chronic bronchitis (Diagnostic Code 6600) or chronic pleural effusion or fibrosis (Diagnostic Code 6844), but do not combine that evaluation with any of the above evaluations.  

• Review special provisions regarding the evaluation of specific respiratory conditions under 38 CFR 4.96(a) - Rating co-existing respiratory conditions