Several methods can be used to accurately diagnose the source of a breathing problem. A physician will perform a physical exam, including a careful examination of the lungs, heart and upper-airway passages.  The physician will also collect the patient’s medical history, including current medications, and inquire about the details of the breathing problem. Questions a physician may ask will often involve the following:

Breathing quality

• Do you notice shortness of breath?
• Do you make grunting sounds while breathing?
• Do you have to work hard to breathe?

Time pattern

• What is the duration of breathing problems (months or years)?
  
  
• Did the breathing problems begin recently or suddenly?
  
  
• Do the breathing problems develop gradually and have they worsened recently?
  
  
• What is the length of time that breathing problems last?
  
  
• Does each repeated episode follow the same pattern and does the level of the problem change?
  
  
• Does the breathing problem cause loss of sleep (paroxysmal nocturnal dyspnea)?

Aggravating factors

• Did breathing problems develop within 4 to 6 hours following exposure to a possible allergen (such as pollen or pet dander)?
  
  
• Does the breathing problem get worse with a change in body position?
  
  
• Does lying flat aggravate the problem (orthopnea)?
  
  
• Does exercise aggravate the problem?
  
  
• Is wheezing associated with shortness of breath?

Diagnostic tests also can help pinpoint the nature of the problem. Such tests include:

• Pulmonary function test. Reveals how much air is in the lungs and how quickly it is exhaled.
  
  
• Spirometry. Measures how much air a person blows out in a fixed period of time, and how forcefully it is blown. It also can reveal the extent of airway obstruction present.
  
  
• Arterial blood gas analysis. Measures concentrations of oxygen and carbon dioxide present in a blood sample taken from an artery.
  
  
• Echocardiogram. Uses sound waves to create a picture of the heart.
  
  
• Chest x-ray. Uses low doses of radiation to produce an image of the chest.
  
  
• Electrocardiogram (EKG). Records the electrical activity of the heart.
  
  
• Stress test. Takes EKG readings of the heart while a person exercises.
  
  
• CAT scan of the chest. Creates a picture of the chest and upper abdomen.
  
  
• Sputum culture. Checks for the presence of bacteria in coughed-up mucus.