What is pulmonary hypertension?
Pulmonary hypertension is a rare lung disorder in which the arteries that
carry blood from the heart to the lungs become narrowed, making it difficult for
blood to flow through the vessels. As a result, the blood pressure in these
arteries -- called pulmonary arteries -- rises far above normal levels. This
abnormally high pressure strains the right ventricle of the heart, causing it to
expand in size. Overworked and enlarged, the right ventricle gradually becomes
weaker and loses its ability to pump enough blood to the lungs. This could lead
to the development of right heart failure.
Pulmonary hypertension occurs in individuals of all ages, races, and ethnic
backgrounds although it is much more common in young adults and is approximately
twice as common in women as in men.
Why do the pulmonary arteries narrow?
Scientists believe that the process starts with injury to the layer of cells
that line the small blood vessels of the lungs. This injury, which occurs for
unknown reasons, may cause changes in the way these cells interact with the
smooth muscle cells in the vessel wall. As a result, the smooth muscle contracts
more than normal and narrows the vessel.
What are the symptoms of pulmonary hypertension?
Symptoms of pulmonary hypertension do not usually occur until the condition
has progressed. The first symptom of pulmonary hypertension is usually shortness
of breath with everyday activities, such as climbing stairs. Fatigue, dizziness,
and fainting spells also can be symptoms. Swelling in the ankles, abdomen or
legs; bluish lips and skin, and chest pain may occur as strain on the heart
increases. Symptoms range in severity and a given patient may not have all of
the symptoms.
In more advanced stages of the disease, even minimal activity will produce
some of the symptoms. Additional symptoms include irregular heart beat
(palpitations or strong, throbbing sensation), racing pulse, passing out or
dizziness, progressive shortness of breath during exercise or activity, and
difficulty breathing at rest. Eventually, it may become difficult to carry out
any activities as the disease worsens.
What causes pulmonary hypertension?
The following are some known causes of pulmonary hypertension:
- The diet drug "fen-phen." Although the
appetite suppressant "fen-phen" (dexfenfluramine and phentermine)
has been taken off the market, former fen-phen users have a 23-fold increase
risk of developing pulmonary hypertension, possibly years later.
- Liver diseases, rheumatic disorders, lung conditions.
Pulmonary hypertension also can occur as a result of other medical
conditions, such as chronic liver disease and liver cirrhosis; rheumatic
disorders such as scleroderma or systemic lupus erythematosus (lupus); and
lung conditions including tumors, emphysema, chronic obstructive pulmonary
disease (COPD), and pulmonary fibrosis.
- Certain heart diseases. Heart diseases including aortic
valve disease, left heart failure, mitral valve disease, and congenital
heart disease can also cause pulmonary hypertension.
- Thromboembolic disease. A blood clot in a large
pulmonary artery can result in the development of pulmonary hypertension.
- Low-oxygen conditions. High altitude living, obesity,
and sleep apnea can also lead to the development of pulmonary hypertension.
- Genetic predisposition. Pulmonary hypertension is
inherited in a small number of cases. Knowing that someone in the family had
or has pulmonary hypertension should prompt you to seek early evaluation
should symptoms occur.