What you need to know about pneumonia: symptoms, causes, and treatment

Pneumonia is a common condition that affects more than 220,000 people in the UK each year. But why is it so common, and how can you tell if you have a milder form or a more serious form of pneumonia? We went to consultant respiratory physician Dr Andrew Barlow for the answers…

What is pneumonia?

Pneumonia is the combination of an acute respiratory illness and a chest x-ray which shows new shadowing that wasn't previously known about.

By acute, we mean short lived. In other words, the patient was well up until a few days ago and then developed the classic range of symptoms, which include:

• fever
• generally feeling unwell
• chest pain
• a cough.

They may be coughing up phlegm, which is often a purulent or yellow.

When these symptoms are in combination with the x-ray result described above, we would make the diagnosis of pneumonia.

Are there different types of pneumonia?

Pneumonia can be classified in a number of different ways.

• You can consider where the patient contracted the infection. You would classify the patient was having either a community acquired pneumonia or a hospital acquired pneumonia.
• You can think about the type of organisms, which can be the bacteria, viruses, or fungi, that are the responsible for pneumonia.
• You can also classify the pneumonia in terms of its severity. In the majority of people, pneumonia can be a relatively mild illness, but as in many cases in medicine, patients can present with a spectrum of severity from mild to the life-threatening.

What causes pneumonia?

I think it's helpful to separate the question out into two parts. Firstly, think about the potential organism that the patient's contracted that's causing the illness. And then secondly, think of it at the level of the lung.

The most common causes of pneumonia are organisms that come from either a virus, bacteria, or more rarely a fungal infection.

Dealing with the second area which is at the lung and airway level, pneumonia is where the air sacks fill up with fluid, so the lung becomes consolidated or solid – and that's what you can see on the chest x-ray.

This is what distinguishes pneumonia from bronchitis, which has similar symptoms, but is in effect an inflammation of the airway lining.

Pneumonia is a more serious infection, and it is an infection that can lead to more severe consequences. So, we always take it very seriously.

Is pneumonia contagious?

The simple and very short answer is yes.

Pneumonia is an infection which is reliant upon host-to-host transmission, so to be successful and to continue, it needs to be passed on from one person to another.

However, the relative ease with which infection is passed from individual to individual can vary depending on the organism.

Many of us have seen the slow motion photography, watching somebody sneeze, and the velocity of the micro droplets that emanate out from the patient. When that happens, some of those micro droplets will contain bacteria or virus.

So you can see how easy it is to either touch a surface which has had the organism on it, or even to inhale micro droplets directly in the air.

How is pneumonia treated?

The majority of patients that develop pneumonia often don't get diagnosed as such.

They will contact a GP and complain of the common symptoms of breathlessness, cough, fever, phlegm, sometimes pleurisy. The GP will then make a clinical assessment and provide a course of antibiotics. For the majority of these patients, that is absolutely the right approach to take.

If the patient is sick enough to warrant hospital admission then our approach is very different.

The patient has a formal assessment which includes a medical history where we talk to the patient, and understand the sequence of events that led up to the day.

We examine the patient, and we rearrange for a variety of tests, including an imaging test to confirm pneumonia, and a variety of blood tests and sputin tests to assess the severity of the illness, its impact on other organ systems, and the cause of organism.

If we believe the patient has a viral cause, the test, the kits that we use will allow us to pinpoint exactly what virus. It may be one of the subtypes of influenza for example - then we will consider anti-influenza medication such as Tamiflu.

If, however, we believe it to be a bacterial infection, treatment would be primarily antibiotics. The type of antibiotic would be in part determined by the severity of illness and in part determined by what information we have initially as the potential cause.