What is Pulmonary Arterial Hypertension?
- Ishaan Bhaduri
- 12 minutes ago
- 3 min read
Pulmonary Arterial Hypertension (PAH) is a rare condition characterized by high blood pressure in the pulmonary arteries. The pulmonary arteries are the blood vessels that carry blood from the right side of the heart to the lungs. The increased blood pressure can cause blood to back up in the right side of the heart. The right ventricle stretches like a water balloon, crowding out the left ventricle, making that smaller and less effective at pumping blood. A backup of blood can lead to right-sided heart failure. PAH is most common in women ages 30-60.
Cause
The causes of PAH are usually unknown (aka idiopathic). However, there can be some possible causes. For example, genetic mutations such as the BMPR2 gene can cause PAH. Connective tissue disorders like scleroderma or congenital heart diseases can contribute as well. Portal hypertension, the use of stimulant drugs (such as cocaine or amphetamines), and HIV infections can contribute to the development of PAH.
Symptoms
Symptoms of PAH can vary depending on the severity of it. If the person is in the initial phases of the condition, then shortness of breath, fatigue, general weakness, chest pain, dizziness, and fainting are all possible symptoms. As the condition progresses, symptoms such as coughing up blood (hemoptysis) and hoarseness of the voice can arise. Severe or untreated PAH can result in right-sided heart failure. Heart failure can result in edema, or the swelling of the face and lower limbs, and ascites, or fluid in the abdomen. Liver enlargement can also be caused by heart failure. In the final stages of PAH, low blood oxygen levels (due to a failed heart and backed up blood) can cause the skin to take on a bluish appearance (cyanosis).
Diagnosis
PAH’s diagnosis is based on exclusion. This means that the other causes of pulmonary hypertension must be ruled out first in order to confirm a diagnosis. Initial signs of PAH can be seen with a chest X-ray or with an echocardiogram (ECG or EKG). This is to evaluate the structure and function of the heart. The most definitive method of diagnosis is using a right heart catheterization to measure the pressure in the blood vessels of the lungs.
A right heart catheterization has three main steps. First, a catheter is placed into a large vein in your body, which is usually the jugular vein in the neck, or the femoral vein in the leg. Then, the catheter is threaded into the right side of the heart through that vein. Finally, a monitor records the pressure in the right side of the heart and in the pulmonary arteries. This is the best method because the measurement of blood pressure in the pulmonary arteries is quite direct.
Some other tests include blood tests, CT scans, heart MRIs, and even a six (6) minute walk test. The six minute walk test is for the healthcare provider to test how much exercise you can handle and how much oxygen circulates in your body while you move.
Treatment
Treatment for PAH includes therapies such as diuretics to manage swelling and help the body remove excess fluid, supplemental oxygen, and blood thinners to prevent clots. Calcium channel blockers help by lowering blood pressure. Dilating blood vessels is also a viable treatment for PAH. Medications for dilating blood vessels tend to target one of the three pathways: prostacyclin, endothelin, or nitric oxide pathways. The most extreme treatment of PAH is for irreversible cases: a double lung transplant.
Conclusion
PAH, or Pulmonary Arterial Hypertension, is a potentially life-threatening cardiovascular condition that should be identified as soon as possible. It is caused by a building of blood in the right side of the heart, crowding out the left ventricle, leading to overall worse heart pumping performance. The diagnosis is strict and requires absolute surety, and treatment plans vary on the symptoms present.
References
Pulmonary arterial hypertension. American Lung Association. Accessed September 5, 2025. https://www.lung.org/lung-health-diseases/lung-disease-lookup/pulmonary-arterial-hypertension
Pulmonary arterial hypertension. Cleveland Clinic. Accessed September 5, 2025. https://my.clevelandclinic.org/health/diseases/23913-pulmonary-arterial-hypertension
Pulmonary arterial hypertension and your body. WebMD. Accessed September 5, 2025. https://www.webmd.com/lung/story/pulmonary-arterial-hypertension-body
Lai YC, Potoka KC, Champion HC, Mora AL, Gladwin MT. Pulmonary arterial hypertension: the clinical syndrome. Circulation Research. 2014;115(1):115-130. doi: 10.1161/CIRCRESAHA.115.301146
Laguaite M. What is Pulmonary Arterial Hypertension?. WebMD. Published April 19, 2025. Accessed September 5, 2025. https://www.webmd.com/lung/pulmonary-arterial-hypertension
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