Objective: The purpose of this article is to review the medical history and physical examination of the asthmatic patient.
Data sources: English references identified from relevant articles and book chapters, experts, and MEDLINE search, using "asthma," "physical diagnosis," and "medical history."
Study selection: Clinical studies of the medical history or physical examination in subjects with respiratory disease were selected for review.
Results: Symptoms such as wheezing, chest tightness and difficulty in taking a deep breath suggest asthma, while symptoms such as gasping, smothering or air hunger suggest alternative diagnoses. Symptoms of asthma correlate poorly with airway obstruction in one-third to one-half of asthmatic patients. Respiratory signs such as wheezing, breath sound intensity, forced expiratory time, accessory muscle use, respiratory rate and pulsus paradoxus correlate roughly with airway obstruction. However, clinicians disagree on the presence or absence of respiratory signs 55% to 89% of the time. Furthermore, physicians correctly predict pulmonary function based on history and physical examination only about half the time, and correctly diagnose asthma based on the clinical examination 63% to 74% of the time.
Conclusions: The medical history and physical examination are moderately effective in diagnosing asthma and estimating its severity. Objective measures of lung function are necessary for the accurate diagnosis of asthma.