Journal of pain and symptom management
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Dyspnea is frequently a multicausal and devastating symptom among advanced cancer patients. It occurs in 21%-78.6% of patients days or weeks before death and is often difficult to control. The genesis and pathophysiology of dyspnea as a symptom still has not been well understood. ⋯ This might also explain why about 24% of dyspneic cancer patients do not present cardiac/pulmonary disease. In addition, two other possible mechanisms of dyspnea have been proposed: chemoreceptor stimulation and efferent activity from the respiratory center by direct ascending stimulation. These factors and the assessment tools used in patients with chronic dyspnea are summarized in this review.