Chronic obstructive pulmonary disease (COPD)

Smoker's cough

Chronic obstructive pulmonary disease, also known as "COPD", destroys the lungs slowly, but forever! Prevention is possible by avoiding the triggers of the disease, especially smoking. The disease cannot be cured, but there are treatment options that improve the course and quality of life and prolong life expectancy.

Overview: What is chronic obstructive pulmonary disease?

Chronic obstructive pulmonary disease is known as COPD. This is an impairment of lung function due to a narrowing of the airways and the development of pulmonary emphysema. The airways narrow because the bronchial mucosa is permanently inflamed and thus thickened. In addition, the lungs are over-inflated because lung tissue around the alveoli is destroyed, which impairs gas exchange (pulmonary emphysema). The changes in the airways and lungs cannot be reversed. The disease is not contagious.

Frequency: COPD is widespread among smokers

Around 1.3 percent of the population develop COPD every year. In Switzerland, it is estimated that around 400,000 people over the age of 40 suffer from chronic obstructive pulmonary disease. Based on death certificates, around 4,000 people die from it every year.

Causes and risk factors: Inhalation of harmful substances

The cause of chronic obstructive pulmonary disease is that the lungs and airways are permanently exposed to harmful substances.

The majority of people affected are smokers. Every second older person who smokes develops chronic obstructive pulmonary disease. However, the risk of disease also depends on the amount of tobacco consumed. Former smokers can also develop COPD, as can passive smokers.

Worldwide, over a third of all people with chronic obstructive pulmonary disease are non-smokers. Experts attribute the disease primarily to exposure to the air they breathe due to the combustion of biological material (e.g. cooking on an open fire in inadequately ventilated rooms).

In a few cases, COPD has a genetic cause. This is a deficiency of a specific enzyme (alpha-1-antitrypsin deficiency). Patients with this disease can benefit from enzyme therapy and are included in a national registry. This national register is managed by the USZ on behalf of the FOPH.

Symptoms: Cough with sputum and shortness of breath

Chronic obstructive pulmonary disease typically manifests itself with sputum production, coughing and shortness of breath, the so-called “AHA symptoms”. The symptoms worsen with respiratory infections, for example.

Complaints can be exacerbated by other influences:

  • Tobacco smoke,
  • Inhalation of exhaust fumes,
  • Kitchen fumes,
  • Perfume,
  • extreme heat or cold and
  • High humidity


Initially, shortness of breath only manifests itself during physical exertion, but later, when irreversible damage to the airways and lungs develops, it can also occur at rest. In severe cases, other symptoms are added, such as poor performance, low physical resilience, muscle loss and weight loss.

A typical feature of chronic obstructive pulmonary disease is that it often remains undetected until it reaches an advanced stage. This is why a timely diagnosis is very important. To this end, the World Health Organization has established the Global Initiative for Chronic Obstructive Lung Disease, also known as GOLD (Global Initiative for Chronic Obstructive Lung Disease). The aims of this initiative are to improve the diagnosis and treatment of the disease and to inform the population about it.

Focus on pulmonary function tests

To diagnose chronic obstructive pulmonary disease, a medical history and physical examination are important. If we suspect COPD, we ask the person concerned about their symptoms and risk factors. Then we examine the lungs by tapping and listening to them. There are often similarities with other diseases, such as bronchial asthma or cardiac insufficiency. The differential diagnosis between COPD and other diseases can be supplemented with the following examinations:

  • Spirometry: During spirometry, the respiratory volume and airflow velocity are measured. We use the values to assess the lung function. You simply breathe in and out via a mouthpiece-tube system. We use a special sensor to measure the air flow during breathing.
    In chronic obstructive pulmonary disease, the airflow values are impaired during exhalation. Two values are particularly important here:
  • The FEV1 value (“Forced Expiratory Volume in 1 second”), i.e. the largest amount of air that a person can exhale in one second
  • The FVC value (Forced Vital Capacity), i.e. the amount of air that a person can exhale at maximum speed after taking a deep breath.

Normally, the FEV1/FVC ratio is 75 percent or more. The ratio is significantly lower in people with chronic obstructive pulmonary disease.

  • Allergy test: This is used to rule out bronchial asthma.
  • Blood tests: They help us to detect concomitant diseases.
  • Blood gas analysis: The oxygen and carbon dioxide levels in the blood are measured.
  • X-rays or computer tomography: X-ray images of the chest show overly bright lung fields, flattened diaphragms and often a bell-shaped structure of the chest.
  • Bronchoscopy: Using a flexible catheter equipped with a mini-camera, which is inserted through the mouth into the airways, we can see the mucous membranes of the trachea and bronchi. It can also be used to take tissue samples.

COPD: Determining the degree of severity according to GOLD

Based on international criteria, the severity of chronic obstructive pulmonary disease can be determined. This is important for the prognosis and treatment of the disease and takes place in two stages.

Step 1: Assessment of lung function

Based on the spirometry values, there are four classes, from GOLD 1 (minor impairment of lung function) to GOLD 4 (major impairment of lung function).

Classes according to GOLD FEV1 FEV1/FVC
1 (light) 80 percent < 70 percent
2 (medium) 50 to 79 percent < 70 percent
3 (heavy) 30 to 49 percent < 70 percent
4 (very heavy) Less than 30 percent < 70 percent

Step 2: Determining the severity of the symptoms

Based on the frequency of episodes in the past 12 months (exacerbations) and the severity of the symptoms, there are four groups, from A (low) to D (high).

Group Number of exacerbations Symptoms
A 1 per year few
B 1 per year increased
C 2 per year or more few
D 2 per year or more increased

Step 1 and step 2 are combined. An affected person with GOLD 2 class in group B has GOLD 2 B severity. We base the treatment on this.

The COPD questionnaire

With the help of a special questionnaire, you as the person affected can assess for yourself how severe your COPD symptoms are. The following is queried and marked with 0 to 5 points:

  • Frequency of coughs
  • Quantity of sputum
  • Existence and severity of chest tightness
  • Breathlessness when walking uphill or climbing stairs
  • Restriction of domestic activities
  • Restriction of activities outside the home
  • Quality of sleep
  • Lack of energy

If the questionnaire is scored with less than 10 points, the severity of the disease is mild. With more than 30 points, the quality of life and resilience are severely and permanently restricted.

Prevention, early detection, prognosis

The best way to prevent chronic obstructive pulmonary disease is to avoid the risk factors, especially smoking. If you already have COPD, it is advisable to avoid possible complications by getting vaccinated against diseases or pathogens that put a lot of strain on your airways – in particular against influenza every year and against pneumococci.

Course and prognosis

COPD cannot be cured and the damage to the lungs is irreversible. The prognosis of chronic obstructive pulmonary disease depends on the severity of the disease and the correct treatment. Abstaining from tobacco consumption improves the course of the disease. It is also important to avoid complications such as pneumonia or heart failure. Depending on the age and severity of the disease, life expectancy can be influenced by appropriate behavior and treatments.

Self-help groups

The exchange with people who are affected by the same disease can be a great support in coping with the disease. Advice on finding a suitable self-help group is available from Selbsthilfe Zürich. Self-Help Zurich and the University Hospital Zurich are cooperation partners in the national project “Health literacy thanks to self-help-friendly hospitals”.