Causes Of Pulmonary Hypertension

1. Pulmonary Arterial Hypertension (PAH)

Primary or idiopathic pulmonary arterial hypertension can occur without a known cause, though it may also be linked to genetic factors such as gene mutations. In some cases, it is associated with congenital heart defects or the use of certain appetite-suppressant drugs in older children. Additionally, patients may experience PAH in conjunction with connective tissue disorders. Another unique scenario involves persistent pulmonary hypertension caused by heart failure, where the increased pressure in the left side of the heart is transmitted to the pulmonary arteries.

2. Left-Sided Heart Disease

Conditions affecting the left side of the heart, such as left ventricular dysfunction or cardiomyopathy, can also lead to pulmonary hypertension. Structural issues like valvular stenosis impair the heart's ability to pump blood efficiently, increasing pressure within the pulmonary circulation. This type of pulmonary hypertension is classified as Group 2 and is often related to long-term left heart failure.

3. Lung Diseases And Hypoxia

Chronic lung conditions, including chronic obstructive pulmonary disease (COPD), are known contributors to pulmonary hypertension. In premature infants, bronchopulmonary dysplasia can lead to chronic lung disease, resulting in prolonged hypoxia. This lack of oxygen causes vasoconstriction and vascular remodeling, ultimately increasing pulmonary artery pressure. Other rare causes include chronic thromboembolic pulmonary hypertension, where blood clots persistently block the pulmonary arteries.

4. Hematologic And Metabolic Disorders

Certain blood-related conditions, such as chronic anemia or polycythemia, can alter the dynamics of blood flow and contribute to pulmonary hypertension. Similarly, rare metabolic diseases like glycogen storage disorders or thyroid dysfunction may also play a role. These causes are less understood and often require specialized diagnostic approaches to identify and manage effectively.