Overview: General clinical information for PH

Pulmonary hypertension is an uncommon disorder characterized by an increase in the blood pressure in the blood vessels of the lungs. There are many different causes of PH, and evaluation of a patient with possible PH has 3 main goals:

1. Determination of whether the patient truly has PH and its severity
2. Determination of the cause of the PH
3. Assessment of the best treatment

The treatment of PH depends on the cause, and treatment of many causes has improved significantly over the past 10 years. Diagnosis and treatment is a complicated process, and in general we recommend that most patients have at least an initial evaluation at a center that specializes in PH.

Definition

Blood pressures are usually reported with a top number (the “systolic” pressure) and a bottom number (the “diastolic” pressure), and there is also an average pressure that falls in between (the “mean” pressure).

For example, if the blood pressure in your arm is 120/80, 120 is the systolic pressure and 80 is the diastolic pressure. The mean pressure would be about 93, but typically is not mentioned.

Blood pressure in the lungs, or pulmonary artery pressure (PAP), is normally much lower than pressure in the arms, usually around 20/10 with a mean of 13.

Pulmonary hypertension is defined as a mean PAP greater than 25 mm Hg at rest, or a mean PAP greater than 30 mm Hg during exercise. The severity of the PH can be further classified below:

Classification	Pulmonary Artery Pressure (PAP) PAP
Borderline	Mean PAP 21-25 mm Hg OR Systolic PAP 31-40 mm Hg
Mild	Mean PAP 26-30 mm Hg OR Systolic PAP 41-50 mm Hg
Moderate	Mean PAP 26-30 mm Hg OR Systolic PAP 41-50 mm Hg
Severe	Mean PAP >40 mm Hg OR Systolic PAP >70 mm Hg