What is PH?

Pulmonary Hypertension (PH) is high blood pressure in the blood vessels of the lungs. The name comes from pulmonary, or having to do with the lungs, and hypertension, which means high blood pressure. If the high blood pressure in the lungs is due to narrowing of the pulmonary arteries, it is known as pulmonary arterial hypertension (PAH). PAH is usually caused by disease in the large or small pulmonary arteries, but in nearly all cases, the small pulmonary arteries are eventually affected. It is not known how the disease starts, but three processes are known to be involved: vasoconstriction, or narrowing of the blood vessels in the lungs; proliferation or scarring of the blood vessels that makes them stiffer and thicker, narrowing the blood vessels further and in some cases blocking them completely; and thrombosis or clotting, which also contributes to narrowing of the blood vessels. When the blood pressure inside the pulmonary vessels is high, the right side of the heart has to work harder to pump blood into the lungs in order to pick up oxygen. This over-exertion can lead to failure of the right side of the heart.

Although uncommon, PH affects males and females of all ages and ethnic background. PH is often not diagnosed in a timely manner because its early symptoms can be confused with other conditions, such as asthma, and it may be incorrectly treated on this basis. Patients with mild PH may have no symptoms. Patients with moderate or severe PH usually notice shortness of breath (dyspnea), especially with exercise. Patients may also notice unusual chest pains and symptoms of right-sided heart failure, such as worsening shortness of breath and swelling of feet and legs. Other symptoms that patients cite include cough, light headedness or fainting, palpitations (heart racing or fluttering), and swelling.