Difference Between Pneumonia and Chest Infection

Chest infection is a broad term that covers any kind of viral, bacterial, fungal or parasitical infections that occur anywhere in the respiratory system including both upper and lower respiratory tract. Pneumonia is just a one entity that belongs to the chest infections. Some people may mistake as these two terms referring to the same disease, but they are not. This article is to point out the differences between these two terms. If someone has pneumonia, he gets chest infection, but when someone has chest infection, it does not necessarily imply pneumonia; it could be something else.

Pneumonia

Pneumonia is an acute infection of the lung; it can occur as a primary disease in a healthy individual, due to highly virulence organism or more commonly as a complication, which affects many seriously ill hospitalized patients. It represents 5-12% of all lower respiratory tract infections and increased incidence is seen in very young and elderly population.

Acute pneumonias are again broadly classified as air space pneumonia and interstitial pneumonia depending on which part of the lung is involved. Air space pneumonias are again divided as lobar pneumonia and bronchopneumonia according to the pattern of involvement of the lung. The pathological process of pneumonia progress through four phases, namely: congestion, red hepatisation, gray hepatisation, and finally resolution with little or no scarring.

Clinically patient presents with fever, rigors, vomiting and cough. At the beginning, the cough may be non-productive, but as the disease progress, it may become mucopurulent.

Once the patient comes with these symptoms, the doctor has to have some differential diagnoses, which can mimic the same disease. They include pulmonary infarction, tuberculosis, pulmonary edema, pulmonary eosinophilia, malignancy, and some other rare conditions.

Complications of the disease include disturbances of ventilation and perfusion, pleural involvement, bacteremia, suppuration, and necrotizing bacterial pneumonia.

Once the clinical diagnosis is made, the patient should be investigated with a chest X ray, to confirm the diagnosis. Other laboratory investigations include microbiological studies, arterial blood gas, gas exchange and general blood tests, which will be helpful in diagnosing and assessing the complications of the disease.

If the patient is not severely ill, he can be managed at home with close observation. If not, the patient should be admitted to the ward. Principles of management include bed rest, oxygen therapy, anti bacterial therapy and physiotherapy.

Chest Infections

As mentioned above, chest infections are a broad term. It includes any sort of infection, in any part of the respiratory system. It could be an upper respiratory tract infection or Lower respiratory tract infection. The common conditions are pneumonia and acute bronchitis where the latter is the commonest. So once the patient comes with those classical symptoms of chest infection the doctor has to differentiate from which disease the patient is suffering from.