What are the causes or risk factors for emphysema? 

• The main cause of emphysema  is smoking, which activates inflammatory cells in the lung. This inflammation causes; 1) swelling within the bronchioles, and 2) activation of enzymes called proteases which attack and destroy lung tissue (the alveolar wall structures). 
• There  is a genetic predisposition to emphysema.  The relatively rare condition known as alpha 1-antitrypsin deficiency is  the genetic deficiency  of a chemical that protects  the lung  from damage by proteases. 
• Emphysema is also a component of aging. As the lungs get older, the elastic properties decrease, and the tensions that develop can result in small areas of emphysema. 

Other less common causes of emphysema include: 

• Intravenous drug use in which some of the non-drug additives like corn starch can be toxic to lung tissue 
• Immune deficiencies in which infections like Pneumocystis carinii can cause inflammatory changes in the lung 
• Connective tissue illnesses (Ehlers-Danlos Syndrome, Marfan syndrome) in which abnormal elastic tissue in the body can cause alveoli to fail

In underdeveloped countries, a common cause of emphysema is indoor air pollution. In these populations, it is very common to have indoor stoves in  the kitchen. The smoke from cooking results in the damage to the lungs. 

What are  symptoms of emphysema? 

Emphysema is  a progressive disease that usually manifests itself in patients after 50 years of age. Emphysema  is a subtype  of chronic obstructive pulmonary disease (COPD in  the US, COLD  in the United Kingdom). Most patients, except  in those in whom disease is  the result of a genetic deficiency (alpha-1 antitrypsin deficiency), have variable manifestations of the different components of COPD which include: 

• chronic bronchitis, 
• asthma,  
• emphysema,  and
• bronchiectasis.  

Each of the subtypes has characteristic symptoms; those primarily  associated with emphysema are shortness of breath and wheezing. Initially the shortness of breath (dyspnea) occurs with activity; as time continues and the disease progresses, the episodes of dyspnea occur more frequently eventually occurring at rest.