Learn the three main causes of swollen veins: venous insufficiency, blood clots, and inflammation. Discover symptoms, ...

About 14% of COVID cases are severe, with an infection that affects both lungs. As the swelling worsens, your lungs fill with fluid and debris. You might also have more serious pneumonia.

It occurs when allergens or irritants trigger inflammation (swelling) and narrowed airways, making it harder for air to flow in and out of your lungs. COPD affects about 16 million U.S. adults.