dyspnea

Dyspnea, from the Greek dyspnoia meaning difficult breathing, is the subjective sensation of breathing discomfort that varies in intensity and quality. It is a symptom, not a disease, and can arise from a wide range of conditions affecting the lungs, heart, blood vessels, airways, muscles, or the nervous system. It may be acute or chronic.

Common causes are grouped as cardiopulmonary: pulmonary edema, pneumonia, chronic obstructive pulmonary disease, asthma, interstitial lung disease, pulmonary embolism; cardiac: heart failure, ischemia; anemia, obesity, deconditioning; neuromuscular disorders such as myasthenia gravis or amyotrophy; extrapulmonary factors including anxiety and pain.

In history, onset, progression, associated symptoms (chest pain, fever, cough, syncope, leg swelling) and triggers help distinguish causes. Physical exam may reveal tachypnea, use of accessory muscles, cyanosis, abnormal breath sounds, wheeze, or crackles. Objective measures include oxygen saturation, arterial blood gas, chest imaging, ECG, and, when appropriate, pulmonary function testing.

Dyspnea is typically classified as acute (hours to days) or chronic (weeks or longer). Severity can be described using patient-reported scales such as the Medical Research Council dyspnea scale or the Borg scale, which estimate impact on daily activities or perceived exertion.

Management focuses on treating the underlying cause and relieving symptoms. Supplemental oxygen is used for hypoxemia; bronchodilators for airway disease; diuretics for heart failure; antithrombotic therapy for pulmonary embolism when indicated. In some settings, noninvasive ventilation or mechanical ventilation may be required. Reassurance and addressing anxiety are important adjuncts.

Prognosis depends on the underlying condition and comorbidity burden. Chronic dyspnea is associated with reduced functional capacity and quality of life, and may require multidisciplinary care, including rehabilitation and palliative approaches in advanced disease.