心衰竭與慢性阻塞性肺病是造成急性呼吸衰竭最常見的原因。臨床上，這兩個疾病常常共存，而且互為彼此預後之預測因子。但因為這兩個疾病有相似的臨床症狀與徵候，而且這兩個疾病共存時會彼此遮蔽對方典型的表現，往往造成診斷上的困難，進而忽略了這兩個疾病共存的事實。腦利鈉胜肽可以作為心衰竭與慢性阻塞性肺病急性惡化的鑑別診斷工具，如果腦利鈉胜肽低於100 pg/mL 應可排除心衰竭急性惡化，而當腦利鈉胜肽高於500 pg/mL 時則要高度懷疑心衰竭急性惡化。治療這個共病時也會因為擔心彼此的禁忌症而礙手礙腳，不敢大膽的用藥。本文整理最近的文獻，針對共病之盛行率，彼此對預後的影響，診斷上的盲點及治療上的兩難做深入的回顧。

The coexistence of congestive heart failure and chronic obstructive pulmonary disease is common in patients with acute dyspnea. The frequency of coexistence is far beyond our imagination. Clinical diagnosis is difficult to make because they share common but nonspecific symptoms and signs. Brain natriuretic peptide (BNP) is a useful serum biomarker to differentiate acute exacerbation of congestive heart failure from chronic obstructive pulmonary disease. Acute exacerbation of congestive heart failure could be excluded if BNP level is less than 100 pg/mL.Acute exacerbation of congestive heart failure is highly suspected if BPN level is more than 500 pg/mL. Treatment of this common concomitant disease is usually suboptimal because of being afraid of their contra-indication. To the best of our knowledge, there is no large clinical trial regarding this issue so far. In this review, we try to highlight the comorbidity, prognostic impact, diagnostic confusion and therapeutic dilemma of both diseases.