Emphysema is a chronic (long-term) lung disease, usually caused by smoking. Emphysema is the main form of chronic obstructive pulmonary disease (COPD).
Diagnosing emphysema usually requires pulmonary function tests, combined with a history of symptoms, such as shortness of breath. There is no emphysema cure other than lung transplantation. However, emphysema treatments can improve symptoms and preserve lung function.
Before oxygen therapy is prescribed there are guidelines or criteria that must be met. These criteria involve a blood test. (These blood test criteria must also be met for Medicare and other insurers to pay for the oxygen costs.) Medical experts produced the criteria. They establish what the levels of oxygen in the blood must be for oxygen therapy to be needed.
Doctors begin diagnosing emphysema by recognizing breathlessness in someone with a smoking history. Diagnosing emphysema often includes the following evaluation:
History: A person with emphysema usually describes slowly worsening shortness of breath, over a period of months or years. He or she also likely smoked for many years. Symptoms may also include cough or wheezing.
Physical exam: In mild emphysema, a doctor's examination may reveal no evidence of emphysema. In people with more advanced emphysema, a doctor may notice these findings:
Increased chest size or "barrel chest" (from abnormally expanded lungs in emphysema)
Decreased breath sounds through the stethoscope
Rounded fingertips (clubbing)
Hypoxemia (hypoxia): Low oxygen levels in the blood, detected on pulse oximetry or arterial blood gas testing
Hypercarbia: High levels of carbon dioxide in the blood. This results from an inability to exhale properly in emphysema
Cyanosis: Blue-tinged lips, resulting from low oxygen in severe emphysema
Malnutrition: Muscles slowly waste away in advanced emphysema
Pulmonary function tests (PFTs): A person sits inside an enclosed booth and breathes into a tube. As someone performs various breathing maneuvers, PFTs measure:
How much air the lungs can hold
How rapidly a person can blow out air from their lungs
How much air remains trapped in the lungs after exhalation
Whether any airflow limitations improve with inhaled bronchodilator medicines, such as albuterol
People with normal lungs can blow out most of the air in their lungs in one second. With emphysema, it's more likely to take longer to empty the lungs.
Chest X-ray film: A chest X-ray of someone with emphysema may show abnormally large lungs. In early emphysema, though, a chest X-ray film is usually normal. Diagnosing emphysema can't be done with an X-ray alone.
Computed tomography (CT scan) of the chest: A CT scan in someone with emphysema may show small pockets of air throughout the lung. These areas of damaged lung are where air becomes trapped, making forceful exhalation difficult.
Complete blood count: This simple blood test usually shows normal amounts of white and red blood cells. In advanced emphysema, the red blood cell count may rise. Infections may cause an elevated white blood cell count.