Which statement differentiates orthopnea from trepopnea?

Which statement differentiates orthopnea from trepopnea?

• A. Dyspnea that occurs when standing up is orthopnea
• B. Orthopnea is dyspnea in the recumbent position; trepopnea is dyspnea when lying on one side.
• C. Orthopnea is dyspnea only during sleep; trepopnea is dyspnea during exercise.
• D. Orthopnea and trepopnea are terms for chest pain.

Answer: (B)

The difference lies in how body position affects breathing. Orthopnea is when breathing becomes difficult only after lying down—pulmonary congestion increases when you’re recumbent, a classic sign of left-sided heart failure, and many patients need extra pillows to sleep and feel better when upright. Trepopnea is when dyspnea depends on lying on a specific side, due to asymmetric mechanics in the lungs or heart—conditions like unilateral pleural effusion or unilateral lung disease can cause this positional breathlessness. So the best statement says orthopnea is dyspnea in the recumbent position and trepopnea is dyspnea when lying on one side. Other descriptions—dyspnea upon standing (which points to a different phenomenon), dyspnea only during sleep or during exercise, or chest pain terms—do not capture the distinct positional triggers of these two terms.

The difference lies in how body position affects breathing. Orthopnea is when breathing becomes difficult only after lying down—pulmonary congestion increases when you’re recumbent, a classic sign of left-sided heart failure, and many patients need extra pillows to sleep and feel better when upright. Trepopnea is when dyspnea depends on lying on a specific side, due to asymmetric mechanics in the lungs or heart—conditions like unilateral pleural effusion or unilateral lung disease can cause this positional breathlessness.

So the best statement says orthopnea is dyspnea in the recumbent position and trepopnea is dyspnea when lying on one side. Other descriptions—dyspnea upon standing (which points to a different phenomenon), dyspnea only during sleep or during exercise, or chest pain terms—do not capture the distinct positional triggers of these two terms.