Learn About Chronic Thromboembolic Pulmonary Hypertension (CTEPH) | American Lung Association

Learn About Chronic Thromboembolic Pulmonary Hypertension (CTEPH)

There are many causes of pulmonary hypertension, or high blood pressure, affecting the arteries of the lungs. In some patients, pulmonary embolism, or blood clots, in these arteries can form scar-like tissue which can block or narrow the arteries, leading to a form of pulmonary hypertension called chronic thromboembolic pulmonary hypertension (CTEPH). This condition is difficult to diagnose, often leading to delayed or missed diagnoses. However, once diagnosed, there are treatment options available to patients at medical centers that specialize in this disease.

Key Facts

  • CTEPH is caused by chronic blood clots in the lungs that become scar-like tissue blocking or narrowing the pulmonary arteries.
  • CTEPH can be a cause of persistent shortness of breath that is otherwise unexplained.
  • Many patients can be cured with surgery. In those patients who are not candidates for surgery, medications and other procedures can improve symptoms.

 What Is CTEPH?

After a blood clot in the lungs (called a pulmonary embolism), the majority of patients will regain normal blood flow in the affected arteries after a few months of taking blood-thinning medications. In a minority of patients (about 1 in 25) the clot becomes scar-like tissue despite the proper use of blood-thinners. As these “scars” block blood flow to the pulmonary arteries, the blood pressure increases in these vessels. The normal pressure in the pulmonary arteries is very low (about 25/10 mmHg).The right side of the heart that pumps the blood to the lungs to get oxygen is normally thin-walled. But in CTEPH, as the pressure in the pulmonary arteries increases, the right side of the heart enlarges and eventually begins to fail as the heart becomes over-worked. This strain on the right side of the heart leads to the symptoms of CTEPH.

How CTEPH Affects Your Body

The main complaints of patients with CTEPH are primarily due to the right heart straining to pump blood against the high pressures in the pulmonary arteries. The symptoms begin with shortness of breath, especially with exercise like climbing stairs or walking up inclines. As the disease progresses, fatigue (or feeling excessively tired) and possibly light-headedness or passing out with exercise may develop as the heart fails. The difficulty of pumping blood to the high-pressure pulmonary arteries may cause fluid to back up into the abdomen or cause the legs to swell.

How Serious Is CTEPH?

If untreated, CTEPH is a chronic and progressive disease that leads to heart failure and can result in death. The good news is that many patients can be cured with pulmonary thromboendarterectomy (PTE) surgery. In those that are not surgical candidates, symptoms can be managed with a medication to treat pulmonary hypertension.


    This content was developed in partnership with the CHEST Foundation, the philanthropic arm of the American College of Chest Physicians.


    Approved by Scientific and Medical Editorial Review Panel. Last reviewed December 13, 2016.

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