What Is Pulmonary Hypertension?

Pulmonary hypertension (PULL-mun-ary HI-per-TEN-shun), or PH, is increased pressure in the pulmonary arteries. These arteries carry blood from your heart to your lungs to pick up oxygen.

PH causes symptoms such as shortness of breath during routine activity (for example, climbing two flights of stairs), tiredness, chest pain, and a racing heartbeat. As the disease worsens, its symptoms may limit all physical activity.

Overview

The lower right chamber of your heart, the right ventricle (VEN-trih-kul), pumps blood to your pulmonary arteries. The blood then travels to your lungs, where it picks up oxygen. This oxygen-rich blood is pumped to the rest of your body. (For more information, see the Diseases and Conditions Index article on How the Heart Works.)

Three types of changes can affect the pulmonary arteries and cause PH:

• The walls of the arteries tighten.
• The walls of the arteries are stiff at birth or become stiff from an overgrowth of cells.
• Blood clots form in the arteries.

These changes make it hard for the heart to push blood through the arteries and into the lungs. Thus, the pressure in the arteries rises. Also, as a result of the heart working harder, the right ventricle becomes strained and weak.

The heart may become so weak that it can't pump enough blood to the lungs. This causes heart failure. Heart failure is the most common cause of death in people who have PH.

PH is divided into five groups based on its causes. In all groups, the average pressure in the pulmonary artery is higher than 25 mmHg at rest or 30 mmHg during physical activity. The pressure in a normal pulmonary artery is about 15 mmHg at rest. (The mmHg is millimeters of mercury—the units used to measure blood pressure.)

Usually, other diseases or conditions, such as heart and lung diseases or blood clots, cause PH. Some people inherit the condition. In some cases, the cause isn't known.

Outlook

PH has no cure. However, research for new treatments is ongoing. The earlier PH is treated, the easier it is to control.

Treatments include medicines, procedures, and other therapies. These treatments can relieve PH symptoms and slow the progress of the disease. Lifestyle changes also can help control symptoms.

September 2008