Dyspnea(shortness of breath) is a common complaint of patients with pulmonary disease.
Timing and acuity of onset, exacerbating and alleviating factors, and degree of functional impairment are key elements of the history Associated symptoms such as cough, hemoptysis, chest pain, wheezing, orthopnea, and paroxysmal nocturnal dyspnea, as well as environmental triggers, should be elicited and are helpful in developing a differential diagnosis.
If dyspnea is recent, of sudden onset, and accompanied by chest pain, diseases such as pneumothorax, pulmonary embolism, and pulmonary edema should come to mind. If the dyspnea is long-standing and is slowly progressive, chronic conditions such as chronic obstructive pulmonary disease, pulmonary fibrosis, and disease are in the differential diagnosis. In patients with chronic dyspnea, progression of the condition may be insidious and difficult to assess quantitatively. Clinicians should ask patients how far they can walk on level ground without stopping, whether they can climb a flight of stairs without stopping, and what activities they did 1 year ago that they are unable to do now. Dyspnea may be exertional or resting and episodic or continuous. Episodic dyspnea may have identified trigers, such as exertion, that suggest parenchymal lung disease or cardiac dysfunction, or it may be associated with environmental exposure a feature that suggests asthma or hypersensitivity pneumonitis. Positional dyspnea is a useful symptom. Patients with severe obstructive lung disease, diaphragmatic paralysis, or neuromuscular weakness may have dyspnea immediately on lying down(orthopnea), because vital capacity is reduced when these patients are in the supine position. Paroxsymal nocturnal dyspnea is commonly associated with congestive heart dyspnea occurs several hours after lying down because increased venous return to the heart results in mild in part edema.
Asthma also causes nocturnal because adrenal cortisol secretion is lowest at about a.m. Exercise-induced asthma causes dyspnea out of proportion to the degree of exercise, with dyspnea often most severe in the 15 to 30 minutes after cessation of exercise.
The absence of wheezing does not rule out the presence of wheezing asthma in any setting, and(i.e., asthma does not does not establish the diagnosis always cause wheezing, and not all patients who wheeze (have asthma).