**5. Chronical obstructive pulmonary disease (COPD)**

Chronical obstructive pulmonary disease (COPD) is a chronical inflammatory pulmonary disease [27–29]. The development of COPD usually lasts many years. During these years, bronchial tubes of COPD patients are getting more and more narrowed. COPD is also characterized by attacks of dyspnoea and persistent dry cough. The cough is often accompanied by expectorated mucus. In a late stage, it can cause obstructive, effortful, and painful breathing. These complications can be a hindrance also during simple physical activity. COPD patients are also prone to pneumonia. The main cause of COPD is often smoking. Other contributing factors include the genetic inheritance, a long exposition to dust particles, or a regular and frequent lung infection.

COPD is often divided into two main groups (phenotypes): chronic bronchitis and emphysema.

#### **5.1. Chronic bronchitis**

In chronic bronchitis [28], a typical symptom is a permanent constriction of bronchial tubes. Furthermore, an inhalation of harmful substances cause impairment of the respiratory mucous membrane, while a repeated damage to the membrane makes it thicker and lowers the tissue transparency. As a result, the affected cells increase the production of mucus, leading to the characteristic cough.

#### **5.2. Emphysema**

Emphysema is characterized by a loss of the pulmonary tissue, while the respiratory ways are abnormally widened distantly from terminal bronchioles [28].

The main cause of emphysema is smoking. The substances that are inhaled during smoking are led through the respiratory ways to bronchioles. In bronchioles, the substances provoke a local immune reaction, which is linked with the production of aggressive compounds via leucocytes (mainly free radicals responsible for oxidative stress). This reaction thus initiates a degradation of bronchioles. The afflicted bronchioles merge into huge lung sacs. These sacs have a smaller surface of the pulmonary tissue and thus the gas exchange between lungs and blood is limited.

The second cause of this disease can be disequilibrium between proteases and their inhibitors—anti-proteases. Some COPD patients suffer from the lack of alfa-1-tripsin (an anti-protease), which is the reason for a higher number of proteases in the respiratory ways, which damage the pulmonary tissue [29].

#### **5.3. Asthma and COPD**

**5. Chronical obstructive pulmonary disease (COPD)**

frequent lung infection.

**Figure 3.** Asthma phenotypes.

146 Biomarker - Indicator of Abnormal Physiological Process

Chronical obstructive pulmonary disease (COPD) is a chronical inflammatory pulmonary disease [27–29]. The development of COPD usually lasts many years. During these years, bronchial tubes of COPD patients are getting more and more narrowed. COPD is also characterized by attacks of dyspnoea and persistent dry cough. The cough is often accompanied by expectorated mucus. In a late stage, it can cause obstructive, effortful, and painful breathing. These complications can be a hindrance also during simple physical activity. COPD patients are also prone to pneumonia. The main cause of COPD is often smoking. Other contributing factors include the genetic inheritance, a long exposition to dust particles, or a regular and

COPD is often divided into two main groups (phenotypes): chronic bronchitis and emphysema.

Similar to asthma, COPD is a pulmonary disease and shares many similar symptoms (e.g., pulmonary obstruction, over-production of mucus, attacks of cough and dyspnoea, etc.).


**Table 1.** Asthma and COPD comparison.

Especially, these common characteristics cause that asthma and COPD are sometimes misdiagnosed [30–32]. This can cause an incorrect pharmacotherapy administration, followed by their health state not (or just slightly) improving.

However, several factors can be used to distinguish asthma from COPD (**Table 1**).
