Pneumonia is an inflammation, usually acute, of the lung tissue: it affects both the pulmonary alveoli (small cavities in which gas exchanges between the breathed air and the blood take place ) and the interstitial tissue. In case of pneumonia, there is an accumulation of phlegm , exudate and pus in the lungs, which tend to solidify, preventing the passage of air.
Generally, pneumonia is caused by bacterial, viral or, more rarely, fungal infections. Even the inhalation of liquids or chemical substances, as well as the aspiration of food residues and digestive juices into the tracheobronchial tree , determines the typical inflammatory picture of the disease (in these cases, we speak of aspiration pneumonia ).
Subjects at Risk
The chances of getting sick depend on the health status of the host and are generally higher under two years of age and over 65. The main factors that increase the risk of pneumonia are: upper respiratory tract infections, cigarette smoking , alcohol abuse , heart failure and immunosuppression .
In response to inflammation, the lungs fill with fluid, making normal respiratory function difficult, resulting in dyspnea (shortness of breath). In addition to breathing difficulties , the symptoms of pneumonia often resemble those of a banal flu , with cough , headache , general malaise and fever. Sometimes, acute chest pain, asthma , loss of appetite and nausea also appear .
Diagnosis and Treatment
The diagnosis of pneumonia is made by examining the patient’s chest x-rays , symptoms, and sometimes sputum.
Medical treatment depends on the underlying causes of the disease; in bacterial pneumonia , for example, antibiotics are used , while in viral pneumonia, simple rest for a few days and support therapy are often sufficient to counteract dehydration and dissolve the mucus present in the lungs. In more serious cases, hospitalization and the use of respiratory therapy may be indicated.
To reduce the risk of developing pneumonia, the following are useful: careful hand washing , abstention from smoking and the use of masks to avoid contact with polluting or highly irritating agents. Furthermore, specific vaccines are available to prevent some forms of infectious pneumonia, such as influenza and pneumococcal pneumonia .
Pneumonia: what are the symptoms?
The symptoms of pneumonia can vary, even significantly, in relation to the patient’s general state of health and the cause responsible for the inflammation.
In milder cases, pneumonia resembles the typical symptoms of flu, starting with a slight cough and low-grade fever . Other typical symptoms of this disease are the aforementioned dyspnea ( shortness of breath ), sweating , chills, headache, muscle pain and the unpleasant sensation of general malaise.
Symptoms of Pneumonia
The most common symptoms caused by pneumonia are:
- Dry cough or cough associated with thick, yellow-greenish, brown, or clear mucous phlegm, sometimes streaked with blood ( haemoptysis );
- Breathing difficulty, especially when making efforts;
- Mild fever with chills and sweating;
- Sharp pain in the chest that worsens with breathing or with the effort of coughing;
- Increased frequency of heartbeat and breathing ;
- Easy fatigue and feeling of exhaustion ;
- Nausea and loss of appetite.
Possible complications of pneumonia
If the inflammatory process extends to the superficial areas of the lung, with involvement of the pleura ( pleurisy ), the patient complains of chest pain , accentuated by deep inspiration, coughing and chest movements. Other possible evolutions of pneumonia are respiratory failure , pleural effusion , lung abscess and septicemia . These complications are more common in the most fragile people: elderly people , children and people with other pathologies.
Due to an insufficient immune response, individuals at high risk of complications tend to develop milder initial symptoms, making this disease even more subtle and dangerous. It is no coincidence that pneumonia is often taken as an example of diseases with atypical symptoms in advanced age.
Causes and Risk Factors
Pneumonia: what are the causes?
Under normal conditions, various defense mechanisms protect the body from lung infections. This is the case, for example, of nostril hair, cough, but also eyelashes and bronchial mucus. When pathogens manage to overcome these defenses and reach the pulmonary alveoli, they are promptly attacked by white blood cells . The resulting inflammatory process leads to the accumulation of a protein -rich liquid , called exudate, which fills the alveoli, opposing the normal exchange of respiratory gases. Furthermore, this fluid acts as a culture medium for bacteria and facilitates their dissemination to nearby alveoli.
Pneumonias can be caused not only by bacteria, but also by viruses , mycoplasmas , fungi , and various chemicals.
Pathogenic microorganisms can reach the tracheobronchial tree via four routes:
- by inhalation (pathogens contained in aerosol droplets small enough to reach the alveoli);
- by aspiration (entry of foreign materials into the bronchial tree – usually represented by food residues , saliva or nasal secretions – which can act as a vehicle for the microbes responsible for pneumonia);
- for direct inoculation from adjacent sites;
- by hematogenous or lymphatic diffusion .
Among those listed, the most frequent mechanisms are inhalation and aspiration.
- Extreme age classes (elderly and children)
- Upper respiratory tract infections
- Chronic debilitating diseases, diabetes
- Renal and heart failure
- Alcoholism , smoking
- Air pollution
- Prolonged therapy with immunosuppressants such as cortisone
- Dysphagia , alterations in the state of consciousness
When to consult a doctor
Since pneumonia can become particularly dangerous for the patient’s health, in the presence of shortness of breath, tachycardia , cyanosis , hemoptysis, chest pain, persistent cough , high fever (especially if associated with chills and sweating) or sudden worsening of one’s health condition after a cold or flu, it is best to contact your doctor promptly, especially when the aforementioned risk factors exist.
Bacterial pneumonia can affect anyone, at any age, but has a predilection for debilitated individuals, alcoholics and people with the other risk factors listed in the table. They are the most common cause of pneumonia in adults over age 30.
Some pathogens responsible for bacterial pneumonia are commonly found in the oral cavity and upper airways of healthy people. Taking advantage of a decline in defenses or other predisposing factors, these germs can descend the bronchial tree until they reach the alveoli. Here, the immune response causes the accumulation of fluids, which prevent the normal exchange of gases between the blood and inspired air.
The infection may remain confined or extend to the entire lung; Furthermore, in more severe cases, the bacteria can enter the bloodstream and affect the entire organism, causing very serious or even fatal illnesses.
Among bacteria, Streptococcus pneumoniae , responsible for pneumococcal pneumonia, is the most frequent cause of home pneumonia in all age groups except children. In this case the disease can be prevented by undergoing a specific vaccination .
Other infectious agents of bacterial origin, Gram positive , include Staphylococcus aureus and Streptococcus agalactiae (responsible for pneumonia in childhood), while Gram negatives include Haemophilus influenzae , Klebsiella pneumoniae , Pseudomonas aeruginosa , Escherichia coli and other Enterobacteriaceae .