The lungs consist of gas-transporting airways and functional air spaces, which absorb oxygen and rid the body of excess carbon dioxide. Pulmonary emphysema is a chronic lung condition characterized by overinflation of the lung air spaces and loss of the individual air sacs within those spaces. Emphysema is a form of chronic obstructive pulmonary disease, or COPD. The severity of breathing problems associated with emphysema correlates with the extent of lung involvement.
Shortness of Breath
Shortness of breath is a hallmark symptom of emphysema, notes "The Journal of the American Medical Association" in a patient information page on COPD. The destructive changes in the lungs reduce the efficiency of breathing; less oxygen reaches the bloodstream with each breath. People with mild emphysema experience shortness of breath with physical exertion. Patients with severe disease remain short of breath at rest and typically require supplemental oxygen.
Inability to Take a Deep Breath
The inability to take a deep breath proves a common symptom among people with emphysema, states the American Lung Association. Unlike normal lungs that deflate with exhalation, emphysematous lungs remain abnormally inflated with stagnant, oxygen-poor air. The overinflation leaves little room for further lung expansion, limiting the ability to take a deep breath.
Rapid Breathing
People with emphysema often have abnormally rapid breathing, or tachypnea, notes the medical text "Harrison's Principles of Internal Medicine." With most of the lung air space occupied by stagnant air, the area of the lungs capable of absorbing oxygen and ridding the body of carbon dioxide proves markedly limited. To compensate for the limited working lung volume, the respiratory rate increases.
Prolonged Exhalation
Emphysema causes loss of normal lung elasticity, reports the University of California, San Francisco Medical Center. Lung elasticity forces air out of the lungs during exhalation, much as the elasticity of a blown-up balloon forces the air out upon release of the untied balloon. Loss of normal lung elasticity in people with emphysema necessitates use of the chest muscles to force air out of the lungs during exhalation. This process proves less efficient than the normal exhalation process. Thus, people with emphysema exhibit a prolonged length of exhalation compared to inhalation.
Use of Accessory Muscles
Pulmonary emphysema also alters the mechanics of inhalation. The downward movement of the diaphragm---the muscle that separates the chest and abdominal cavities---normally pulls air into the lungs during inhalation. Lung overinflation with emphysema, however, encroaches on the diaphragm and leaves little room for movement of the muscle.
Without the diaphragm to pull air into the lungs, a person with emphysema must instead use the chest and neck muscles to expand the lungs. Medical professionals describe this phenomenon as use of the accessory muscles of breathing. The rib cage moves upward and the spaces between the lower ribs retract inward with each inhalation. The increased work of breathing associated with emphysema contributes to the chronic fatigue and unintentional weight loss experienced by many people with the disease, notes "The Merck Manual for Healthcare Professionals."
References
- "The Journal of the American Medical Association": Chronic Obstructive Pulmonary Disease Patient Page
- American Lung Association: COPD: Symptoms, Diagnosis and Treatment
- "Harrison's Principles of Internal Medicine, 16th Edition"; Dennis L. Kasper, M.D., et al., Editors; 2004
- UCSF Medical Center: Emphysema, Signs and Symptoms
- The Merck Manual for Healthcare Professionals: Chronic Obstructive Pulmonary Disease
