You have millions of air sacs (alveoli) in your lungs. These air sacs move oxygen into your blood. Alveolar walls contain surfactant. This is a substance made of fats, proteins, and other substances.

Pulmonary fibrosis is a condition that causes lung scarring and stiffness. This makes it difficult to breathe. It can prevent your body from getting enough oxygen and may eventually lead to ...

The pulmonary valve is located between the right ventricle and the pulmonary artery. The valve acts as a doorway that lets blood into and out of the heart. Pulmonary valve stenosis is when the ...

Pulmonary arterial hypertension (PAH) is a type of pulmonary hypertension. It means that you have high blood pressure in the arteries that go from your heart to your lungs. But it’s different from ...