Obesity: Obesity is a risk factor for PH and can cause PH through several mechanisms. It is often associated with heart disease (high blood pressure, heart attacks, heart failure), which is a common cause of PH. It also increases the risk of blood clots in the legs (deep vein thrombosis, DVT) and in the lungs (pulmonary embolism, PE). Patients with PE are at risk of a type of PH called
CTEPH. Obesity increases the risk of obstructive sleep apnea (OSA) and obesity-hypoventilation syndrome (OHS). Both OSA and OHS can cause PH.