Definition: what is pneumonia?Pneumonia is one of the most common respiratory infections. It is a mild infection which affects the lungs, and more precisely the lower respiratory tract. It can be due to different types of germs: bacteria, viruses or fungi.However, in the majority of cases, it is due to a bacterium called pneumococcus. Pneumonia can occur at any age, but is more common in more fragile people, especially young children and older people. Tobacco use, chronic respiratory diseases and immune deficiency are also risk factors of pneumonia.Unlike bronchitis, which only affects the lower airways (bronchi), the lung disease reaches the deep lung and is much less common. The people who are most affected are those with a pulmonary fragility, such as asthma, emphysema, and chronic bronchitis. After the germs present in the air have penetrated the lungs, they travel in the airways to the alveoli where they cause inflammation. Pus and secretions accumulate in these small sacs, causing the symptoms of the disease.Symptoms of pneumonia: how to recognise itSymptoms of pneumonia vary according to the germ responsible and according to the affected person’s health state. The most common signs are:- a high fever (can reach 41°C) with shivering- a cough. Dry at first, it then becomes greasy and can be accompanied by greenish or yellowish secretions.- shortness of breath, an increase in the breathing and heart rate (tachycardia) - more or less significant chest discomfort- chest pain due to the cough or heavy breathingSymptoms can be accompanied by a high fatigue, headaches, nausea, vomiting or even diarrhoea. However, in certain fragile people, pneumonia can present more serious signs such as mental confusion, a significant increase in the heart and breathing rate, hypothermia or a fall in blood pressure.Young children can also experience difficulties in eating, drinking, or even seizures. All these signs mean the patient should quickly consult a doctor.Treating pneumonia: how to treat and prevent it To establish the diagnosis, the doctor will ask the patient about all the signs that they’ve experienced. During the exam, the lungs will be examined in order to find abnormal sounds, but it is a chest X-ray which confirms the diagnosis which will identify the source of the infection.Once the diagnosis is established, treatment will depend on the germ responsible. If it is due to pneumococcus or another bacterium, antibiotics will be prescribed. Treatment generally lasts 7 to 15 days. If the symptoms don’t improve, especially if the fever doesn’t lower, another exam is necessary so that the doctor can prescribe another course of treatment.Generally, pneumonia evolves in about fifteen days, with the fever disappearing 48 to 72 hours later. If the disease is serious or there is a risk of complications, hospitalisation can be necessary. The majority of hospitalised people are babies, young children, older people or immunosuppressed people.Pneumonia can cause complications such as septicaemia, if the germ is in the blood and affects other organs, pleurisy, an inflammation of the pleura or an abscess around the lungs.In those who are at risk (especially over the age of 65), it is possible to receive vaccinations against pneumonia. Made from strains of pneumococcus which is most often responsible, the vaccination called Pneumovax 23 protects against invasive infections which are the most severe and can be fatal. Once treated, the vaccination is effective for life with regard to patients over the age of 65.Those who are affected by another long-term health condition are also advised to get vaccinated, in which case the effectity of the vaccination will vary according to the underlying condition. Whilst some might need a single vaccination, others may need to get vaccinated as often as every five years.