The diaphragm is a thin layer of muscle and tissue that separates the chest and abdominal cavities. It is the main muscle the ...

Your diaphragm is a thin muscle that separates your chest and abdomen. When you inhale, your diaphragm tightens and expands your chest cavity. A paralyzed diaphragm doesn’t tighten as it should when ...

Medically reviewed by Soma Mandal, MD Key Takeaways Heart failure is the most common cause of orthopnea, which is difficulty breathing when lying down.COPD can lead to orthopnea due to lung ...