Chronic obstructive pulmonary disease (COPD)

Causes and risk factors

The most important risk factor for COPD is long‑term exposure to tobacco smoke, with many lifelong smokers developing significant airflow limitation. Passive smoke exposure also contributes. Outdoor and indoor air pollution are relevant in many regions, especially where cooking or heating uses open fires or unventilated stoves; official discussions of this link appear under air pollution. Other contributors include occupational dusts and chemicals, genetic susceptibility, and a history of severe childhood respiratory infections.

• Tobacco smoking: primary cause; see smoking.
• Environmental pollution: household and outdoor sources; see pollution.
• Workplace exposures: fumes, dusts, and chemicals.
• Genetic factors: uncommon causes such as alpha‑1 antitrypsin deficiency.

Symptoms and progression

People with COPD commonly experience increasing breathlessness, a chronic cough, and frequent production of phlegm. Early on, breathlessness may only occur during exertion; as the disease advances it can be present at rest. Exacerbations — episodes of worsening symptoms often triggered by infections — are important events that accelerate decline. Lungs weakened by COPD are more vulnerable to infections of the lung, which can be life‑threatening in severe cases.

Diagnosis and clinical assessment

Diagnosis rests on clinical history and objective testing. Spirometry—measuring forced expiratory volume—confirms persistent airflow limitation. Imaging such as chest X‑ray or CT can show emphysema and rule out alternative diagnoses. Regular assessment tracks symptoms, exacerbation frequency, and functional status. Identifying exposure history (for example smoking or pollution) is a routine part of evaluation.

Management and treatment

The single most effective step to slow progression is stopping tobacco use and avoiding harmful exposures. Treatments focus on relieving symptoms, reducing exacerbations, and improving exercise tolerance. Common approaches include:

• Smoking cessation and exposure reduction.
• Bronchodilator medications to open the airways and ease breathing; see bronchodilators.
• Inhaled steroids for certain patients, pulmonary rehabilitation, oxygen therapy, and, in advanced cases, surgical or bronchoscopic options.
• Vaccination and prompt treatment of respiratory infections.

Prognosis and public health

COPD is a leading cause of chronic illness and disability worldwide; it has been estimated to account for a notable share of global disability burden (disability statistics). Mortality is high in advanced disease and exacerbations contribute substantially to death and healthcare use. The World Health Organization has identified COPD as a major and growing public‑health challenge. Preventive measures that reduce smoking and air pollution are central to lowering the future burden of disease.