Pneumonia  is an acute disease characterized by the development of an inflammatory process in the lungs. Pathology in most cases is of an infectious nature and is most often a complication of respiratory infections.
The lower respiratory system is normally sterile. Constant protection against microorganisms is provided by the cough reflex and mucociliary clearance (production and excretion of bronchial secretions by the ciliated epithelium). Favorable conditions for the development of pneumonia arise when the protective functions are weakened against the background of respiratory diseases, bad habits, immunity disorders, and chronic diseases.
The main manifestations of pneumonia in the classic version are fever and cough. In rare cases (against the background of concomitant pathology), pneumonia is accompanied by atypical and mild symptoms, which complicates timely diagnosis and provision of medical care.
Pneumonia are classified based on the causative organism or mode of infection. The common categories of pneumonia types are discussed below;
This pneumonia is a severe lung disease that deserves attention. It is caused by germs that come into contact with the respiratory system, causing an infection. When the causative agent is a bacterium, we call it bacterial pneumonia.
In other cases, pneumonia can be caused by other organisms such as viruses and, fungi.
Bacterial pneumonia is the most important  and is easily acquired in the community, by the general population. Some bacteria are present in our nose, mouth, throat, skin, and digestive system, which can cause pneumonia when our immunity falls.
Other factors such as smoking and alcoholism facilitate the development of this pneumonia. People who smoke have chronic inflammation of the lungs, which facilitates the development of pneumonia when exposed to infectious agents. Alcohol, on the other hand, reduces immunity  and can alter some defense mechanisms of the respiratory system.
Pneumonia can arise from the community, the so-called community-acquired pneumonia (CAP), or in hospital, called hospital pneumonia. This type of pneumonia is more resistant to antibiotics.
In general, bacterial pneumonia is not contagious or transmissible. Even if someone coughs in front of us, we will only catch pneumonia if our body’s defense mechanisms fail, as in cases of cancer, malnutrition, previous lung or other organ diseases, sleep disturbance, and even stress.
The main symptoms are:
Cough with yellowish or greenish phlegm
Chest pain when coughing or breathing
High fever (above 38ºC)
Shortness of breath
Lack of appetite
Mental confusion in the elderly
Treatment is done at home with antibiotics  and symptomatic for 1 or 2 weeks. The main antibiotics used in adults are amoxicillin, clavulanate, and evofloxacin.
Hospitalization is indicated in cases of elderly people, changes in blood pressure, difficulty in breathing, low blood oxygenation and changes in renal function, or if it is difficult to take medications at home.