pulmonary hypertension

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 heartbeat (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.
  • Genetics. 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.

Pulmonary hypertension may also be caused by other conditions, and in some cases, the cause is unknown.

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