Chronic obstructive pulmonary disease (COPD)

Chronic Obstructive Pulmonary Disease (COPD) is not one single disease but an umbrella term used to describe chronic lung diseases that cause limitations in lung airflow. The more familiar terms 'chronic bronchitis' and 'emphysema' are no longer used, but are now included within the COPD diagnosis.

The most common symptoms of COPD are breathlessness, or a 'need for air', excessive sputum production, and a chronic cough. 
However, COPD is not just simply a "smoker's cough", but a under-diagnosed, life threatening lung disease that may progressively lead to death.

Diagnosis

A chronic obstructive pulmonary disease (COPD) diagnosis is confirmed by a simple test called spirometry, which measures how deeply a person can breathe and how fast air can move into and out of the lungs. Diagnosis of COPD should be considered in any patient who has symptoms of a chronic cough, sputum production, dyspnea (difficult or labored breathing) and a history of exposure to risk factors for the disease. Where spirometry is unavailable, clinical symptoms and signs, such as abnormal shortness of breath and increased forced expiratory time, can be used to help with the diagnosis. A low peak flow is consistent with COPD, but may not be specific to COPD because it can be caused by other lung diseases and by poor performance during testing. Chronic cough and sputum production often precede the development of airflow limitation by many years, although not all individuals with cough and sputum production go on to develop COPD. Because COPD develops slowly, it is most frequently diagnosed in people aged 40 years or over.

Causes

The primary cause of chronic obstructive pulmonary disease (COPD) is tobacco smoke (including second-hand or passive exposure). WHO estimates that in 2005 5.4 million people died due to tobacco use. Tobacco-related deaths are projected to increase to 8.3 million deaths per year by 2030.

The causes for COPD have opposite patterns according to the geographic areas. In high- and middle-income countries tobacco smoke is the biggest risk factor, meanwhile in low-income countries exposure to indoor air pollution, such as the use of biomass fuels for cooking and heating, causes the COPD burden. Almost 3 billion people worldwide use biomass and coal as their main source of energy for cooking, heating, and other household needs. In these communities, indoor air pollution is responsible for a greater fraction of COPD risk than smoking or outdoor air pollution. Biomass fuels used by women for cooking account for the high prevalence of COPD
among nonsmoking women in parts of the Middle East, Africa and Asia. 
Indoor air pollution resulting from the burning of wood and other 
biomass fuels is estimated to kill two million women and children each year.

Costa Rica, Carlos Gaggero, WHO

Using biomass fuels for cooking and heating is the highest risk factor for developing COPD in low and middle income countries.

Other risk factors for COPD include occupational dusts and chemicals (such as vapours, irritants, and fumes) and frequent lower respiratory infections during childhood.

Burden

According to WHO estimates, 80 million people have moderate to severe chronic obstructive pulmonary disease (COPD). More than 3 million people died of COPD in 2005, which corresponds to 5% of all deaths globally. Most of the information available on COPD prevalence, morbidity and mortality comes from high income countries. Even in those countries, accurate epidemiologic data on COPD are difficult and expensive to collect. It is known that almost 90% of COPD deaths occur in low- and middle-income countries.

At one time, COPD was more common in men, but because of increased tobacco use among women in high-income countries and the higher risk of exposure to indoor air pollution (such as biomass fuel used for cooking and heating) in low-income countries, the disease now affects men and women almost equally.

In 2002 COPD was the fifth leading cause of death. Total deaths from COPD are projected to increase by more than 30% in the next 10 years unless urgent action is taken to reduce the underlying risk factors, especially tobacco use. Estimates show that COPD becomes in 2030 the third leading cause of death worldwide.