Chronic obstructive pulmonary disease, or COPD, is a generic term used to describe a combination of lung diseases. COPD (in the United States) most commonly includes two main diseases: emphysema and chronic bronchitis. COPD is a progressive disease that gets worse over time. There is no known cure for COPD, but treatments are available to maintain quality of life. Chronic obstructive pulmonary disease causes coughing fits that produce large amounts of phlegm when the bronchioles become blocked with mucus. “COPD is not just a ‘smoker’s cough,’ but an underdiagnosed and potentially fatal lung disease.” (As stated by WHO, World Health Organization). Chronic obstructive pulmonary disease affects more than 60 million people worldwide. In 2005 alone, more than 3 million people died from COPD. (2005, WHO) People most at risk are smokers, women, especially when biomass fuel is used at home, miners, people with a history of asthma and unemployed, low-income people , divorced, separated or widowed. Two of the most widely bandied about terms COPD are emphysema and chronic bronchitis. These are completely different diseases with their own diagnosis. Although most health organizations classify them as COPD or COPD-related, some institutions do not. Chronic bronchitis is the inflammation and irritation of the lining of the airways (bronchial tubes and bronchioles). The irritation caused by chronic bronchitis leads to an overproduction of mucus, producing blockages in the bronchi and bronchioles. Coughing up thick mucus is common in people with chronic bronchitis. The phlegm produced will often be discolored, yellow or brownish, green or even clear, and will usually be darker and thicker middle of paper......phone booth (body plethysmograph) when inhaling and in a mouthpiece . Changes in pressure inside the box help determine lung volume. Lung volume can also be measured when you breathe nitrogen or helium gas through a tube for a period of time. The concentration of gas in a chamber attached to the tube is measured to estimate lung volume. To measure diffusing capacity, you breathe in a harmless gas, called a tracer gas, for a very short time, often for a single breath. The gas concentration in the air you breathe out is measured. The difference between the amount of gas inhaled and exhaled measures how efficiently the gas passes from the lungs to the blood. This test allows the doctor to estimate how well the lungs move oxygen from the air into the bloodstream. http://www.goldcopd.org/uploads/users/files/GOLD_Report_2011_Feb21.pdf