Generality
Lung disease is the medical term that describes any disease of the lungs capable of compromising the proper functioning of the latter.
According to a widespread classification, pulmonary diseases can be divided into 5 large groups: pulmonary diseases affecting intrapulmonary areas, pulmonary diseases affecting the alveoli, lung diseases affecting intrapulmonary blood vessels, lung diseases affecting the pulmonary interstitium and pulmonary diseases affecting the pleura.
The Respiratory System in a nutshell
The respiratory system is a system that can be subdivided into 3 main components: the airways, the lungs and the diaphragm and intercostal respiratory muscles.
The airways include the nose, the mouth, the pharynx, the nasopharynx, the larynx, the trachea, the bronchi and the bronchioles, and constitute the conduit used to introduce air into the human body and purify it; the lungs are the sites where the human body acquires oxygen from the inhaled air, in place of carbon dioxide (a waste product of the body); finally, the respiratory muscles are the guarantors of the space needed by the lungs to function at their best.
What is a Lung Disease?
Lung disease is the medical expression indicating any disease of the lungs, the presence of which compromises the correct functioning of the latter and, consequently, the so-called respiratory function, ie the physiological process that allows the introduction of oxygen into the human body instead of carbon dioxide.
Lung diseases are, therefore, affections which, by affecting the health of the lungs, impair its function, with negative repercussions on the process of introducing the oxygen essential for the well-being and survival of the human organism.
Causes
A lung disease may be due to:
- Pathogens, such as viruses, bacteria and fungi;
- Cigarette smoke;
- Prolonged contact and / or inhalation of toxic substances (asbestos, silica, etc.) and / or pollutants (eg car exhaust gases);
- Genetic alterations concerning stretches of DNA whose integrity is fundamental to the health of the lungs;
- Neoplastic processes in the lungs or pleura;
- Immune system malfunctions (autoimmune diseases) that specifically affect the health of the lungs;
- Heart diseases (eg severe cardiac arrhythmias, myocardial ischemia, valvulopathies, etc.);
- The intake of certain drugs (eg chemotherapy and some heart medicines), the consumption of injectable drugs and certain medical treatments (eg: radiotherapy);
- Chest trauma.
Types
A lung disease may target intrapulmonary airways, alveoli, intrapulmonary blood vessels, the so-called pulmonary interstitium, and pleura .
Lung diseases affecting the intra-pulmonary airways
With intrapulmonary airways, the anatomists intend the tract of bronchial tree internal to the lungs and including: secondary bronchi, tertiary bronchi, bronchioles, terminal bronchioles and respiratory bronchioles.
Among the lung diseases affecting the intrapulmonary airways, include:
- Asthma ;
- Chronic obstructive pulmonary disease ( COPD );
- Acute bronchitis ;
- Cystic fibrosis .
ASTHMA
Asthma is a chronic pulmonary disease of an inflammatory nature, which determines, usually due to allergens (eg: pollen and animal hair), respiratory infections, medicines (eg NSAIDs), physical exertion, excessive emotions, stress and smoking, the temporary narrowing of intrapolmonary bronchi and bronchioles, thus resulting in an obstacle to the passage of inhaled air.
According to the most reliable hypotheses, asthma would have a genetic origin.
COPD
Chronic obstructive pulmonary disease is the inflammatory lung disease, which causes a permanent narrowing (which is why it is called chronic and obstructive) of the bronchial tree inside the lungs.
In medicine, the term COPD includes two conditions that are surely known to most people, which are: chronic bronchitis ( chronic inflammation of bronchi and bronchioles) and pulmonary emphysema (entrapment, consequent to an excessive narrowing of the air along the intrapulmonary areas) .
The most important causative factors of COPD are, in order, cigarette smoking, passive smoking and prolonged exposure to toxic or polluting substances.
ACUTE BRONCHITE
Acute bronchitis is the inflammation of the bronchi and / or bronchioles in abrupt and sudden appearance.
Normally, at the origin of acute bronchitis episodes, there are viral or bacterial infections.
CYSTIC FIBROSIS
Cystic fibrosis is a serious genetic disease of the hereditary type, marked by malfunctioning of the exocrine glands (such as the pancreas, bronchial glands, intestinal glands, sweat glands and salivary glands). In people with cystic fibrosis, in fact, the aforementioned glands produce an abnormally rich secretion of thick mucus, which is an obstacle to the correct flow of the same secretion and, consequently, a cause of glandular obstruction.
Lung diseases affecting the alveoli
The alveoli, or pulmonary alveoli, are the small sacs located at the end of the intrapulmonary bronchial tree (therefore they are internal pockets of the lungs), in which the air introduced with the inspiration and in which the collection takes place, ends part of the human body, of the oxygen contained in the aforementioned air. All around the alveoli, in fact, take place blood capillaries (alveolar capillaries) which allow the blood, which flows internally, to release carbon dioxide in exchange for oxygen from the air.
In the list of the most important lung diseases affecting the alveoli, they take place:
- Pneumonia ;
- Tuberculosis ;
- Pulmonary edema ;
- Lung cancer ;
- The pneumoconiosis .
PNEUMONIA
In medicine, the term "pneumonia" indicates lung disease sustained by the inflammation of the alveoli.
As a rule, pneumonia has an infectious origin: in most cases ( classical pneumonia ), it is due to the bacteria Streptococcus pneumoniae ( pneumococcus ) and Haemophilus influenzae ; more rarely ( atypical pneumonia ), to the bacteria Mycoplasma pneumoniae and Legionella pneumophila .
TUBERCULOSIS
Tuberculosis is an infectious and contagious disease, which normally affects the lungs, but which could, in reality, also affect other organs of the human body.
Tuberculosis is an example of pulmonary disease affecting the alveoli, because it begins when the pathogen that causes it - the so-called Koch bacillus or Mycobacterium tuberculosis - arrives in the alveolar sacs.
PULMONARY EDEMA
The pulmonary edema consists in the escape of fluids from the capillary system, which surrounds the alveoli, towards the interior of the latter; in other words, pulmonary edema is the medical condition in which we see the transfer of fluids from the capillaries that surround the pulmonary alveoli to the internal spaces of the latter.
The presence of pulmonary edema deprives the alveoli of the ability to fill with air (because in the alveoli there is liquid that should not be there) and this is an obstacle to the gas exchange oxygen - carbon dioxide.
Heart diseases (eg myocardial ischemia) or conditions such as, for example, liver diseases, hypertension of pulmonary veins and occlusion of pulmonary veins may contribute to the formation of pulmonary edema.
LUNG CANCER
Lung cancer is the lung disease resulting from the uncontrolled growth of a tissue cell that makes up the lungs.
This condition is one of the lung diseases affecting the alveoli, as in most cases the aforementioned uncontrolled growth process has an alveolar cell as its protagonist.
Cigarette smoking is the main factor favoring the appearance of lung cancer.
Did you know that ...
Lung cancer arising from the uncontrolled growth of an alveolar cell, as well as from an intrapulmonary bronchial tree cell, is an example of pulmonary adenocarcinoma .
Pulmonary adenocarcinoma is by far the most common type of lung cancer.
PNEUMOCONIOSIS
With the term "pneumoconiosis", doctors mean any lung disease resulting from prolonged and continuous inhalation of organ or non-organic dust.
"Pneumoconiosis" includes numerous medical conditions, including:
- Silicosis due to inhalation of silica dust;
- Asbestosis due to inhalation and contact with asbestos and its dust;
- Berylliosis, due to exposure and contact with beryllium;
- Siderosis caused by the inhalation of ferruginous dust.
Lung diseases affecting the Intrapulmonary Blood Vessels
Lung diseases affecting intrapulmonary blood vessels are lung diseases characterized by a suffering of the last branches of the pulmonary artery, that is the artery which, with origin from the heart, has the task of directing the oxygen-poor blood to the lungs, so as to release carbon dioxide in exchange for oxygen.
The list of pulmonary diseases affecting intrapulmonary blood vessels includes pulmonary embolism and pulmonary hypertension .
PULMONARY EMBOLISM
Doctors speak of pulmonary embolism when a mobile body (which can be an abnormal blood clot, an air bubble, a lump of fat, etc.) goes to wedge and obstruct one of the vessels of the arterial system assigned to transport to the lungs of oxygen-poor blood.
In medicine, the abnormal presence of a mobile body in a blood vessel takes the generic name of embolus .
They can act as emboli: abnormal blood clots, air bubbles, fat clots, lumps of amniotic fluid, cholesterol crystals, talcum granules, some parasites and foreign bodies such as needles or splinters.
PULMONARY HYPERTENSION
Pulmonary hypertension is the abnormal and persistent rise in blood pressure within the pulmonary artery (or one of its branches) and into the cavities of the right heart (ie right atrium and ventricle).
On a purely diagnostic level, doctors talk about pulmonary hypertension when the blood pressure in the pulmonary artery and in the right cavities of the heart exceeds 25 mmHg.
Lung diseases affecting the Pulmonary Interstice
With lung diseases affecting the pulmonary interstitium, the doctors intend to describe the pathologies of the lungs in which there is a suffering of the connective tissue interposed between the alveoli and deputed to give mechanical support to the latter.
The most important lung diseases affecting the pulmonary interstitium are the so-called intersticeopathy and pulmonary fibrosis .
Given the similarity of these two pathologies, the following article only reports the description of pulmonary fibrosis.
PULMONARY FIBROSIS
In medicine, the anomalous and disproportionate formation of scar tissue all around the alveoli takes the name of "pulmonary fibrosis", ie where the interstice extends.
The presence of the aforementioned tissue involves hardening and a decrease in elasticity on the part of the lungs, which, as a logical consequence of the changes just mentioned, lose their normal functionality.
Pulmonary fibrosis can arise due to unknown reasons (idiopathic pulmonary fibrosis) or due to very specific circumstances, such as: prolonged exposure to toxic dust, radiotherapy, prolonged use of chemotherapy or autoimmune diseases such as systemic lupus erythematosus, sarcoidosis or rheumatoid arthritis .
Did you know that ...
In people with pulmonary fibrosis, the lungs are covered with scars, which alter their elasticity and "crush" the adjacent alveoli.
Lung diseases affecting the Pleura
The pleura is the thin serous membrane, composed of two sheets (visceral pleura and parietal pleura), which envelops the lungs and serves to favor their dilation and their activity of gas exchange.
Examples of lung diseases affecting the pleura are: pleural effusion, pneumothorax, pleurisy and pleural mesothelioma .
PLEURAL PAYMENT
The expression "pleural effusion" indicates the abnormal accumulation of fluid within the pleural cavity, ie the space between the visceral pleura and the parietal pleura.
Pleural effusion is a typical complication of pulmonary diseases, such as tuberculosis, pneumonia, pulmonary embolism, asbestosis, lung cancer, etc.
PNEUMOTHORAX
In the medical field, the word "pneumothorax" identifies the anomalous infiltration of air inside the pleural cavity.
The pneumothorax may have a traumatic origin or may depend on other pulmonary diseases (eg: COPD, asthma, cystic fibrosis, tuberculosis, etc.).
PLEURISY
Usually related to viral or bacterial infections, pleurisy is the inflammation of the abrupt and sudden appearance pleura.
PLEURAL MESOTHELIOMA
Pleural mesothelioma is the malignant tumor that originates from one of the cells constituting the pleura.
Mainly related to prolonged exposure to asbestos, pleural mesothelioma is a severe neoplasm, with good infiltrating capacity and discreet metastasizing power.
Symptoms
A generic list of possible symptoms and signs of lung disease certainly includes:
- Dyspnea, ie difficulty in breathing. This is the symptom that characterizes every lung disease, as it is the natural response of the human body to suffering from the lungs;
- Chest pain;
- Cough;
- Recurrent sense of fatigue and tiredness;
- Weight loss for no reason;
- Confusion;
- Sense of fainting (pre-syncope and syncope);
- Tachycardia and / or irregular heartbeat;
- Cyanosis;
- Temperature. With regards to fever, it is important to point out that it is a typical symptom of lung diseases with an infectious origin.
In general, a lung disease of slight clinical relevance is limited to making breathing difficult and causing coughing and slight pain in the chest; on the contrary, a clinically relevant lung disease is responsible for a much more complex symptomatology, which leads to dyspnoea, chest pain and coughing, which is followed by many (if not all, in the most critical cases) of the disorders listed above.
Diagnosis
To formulate the diagnosis of a lung disease and its causes, the following are certainly indispensable: the patient's account of the symptoms, the physical examination, the anamnesis, the pulmonary function evaluation tests and the lung imaging (RX-chest, chest CT and / or chest MRI)
Depending on the circumstances, then, the doctors could follow up the aforementioned investigations with further in-depth examinations, such as: sputum analysis, chest PET, thoracentesis, arterial blood gas analysis and lung biopsy .
Therapy
Where the causes of lung disease are known and treatable, treatment of the condition will include ad hoc causal therapy combined with symptomatic therapy ; when instead the causative factors of a lung disease are unknown or known but incurable, the treatment of the condition will be limited, by force of circumstances, to symptomatic therapy.
To understand…
In the medical field, the set of treatments aimed at contrasting the cause and the factors favoring a certain disease takes the name of causal therapy, while the set of treatments aimed at relieving the symptoms of a certain pathology takes the name of symptomatic therapy and, if possible, slow down its course and delay complications.
Prognosis
The prognosis in the presence of a lung disease depends on:
- The curability of the present condition. A pulmonary disease that can be cured both in the causes and in the symptoms will certainly have a better prognosis than a pulmonary disease that can only be treated in the symptoms;
- Timeliness of diagnosis. Early diagnosis of a lung disease makes the therapy more effective.
