Understanding Pneumonia and Pleurisy

The best way to start understanding any medical condition is to begin with the basics and build up a better knowledge from this point.

Pneumonia is a well-known condition, but how many people actually know what it is, how it develops, and why? Hopefully this article will shed some light on this ailment and give a clearer understanding of what's involved.

Basically pneumonia is an inflammation of the lung usually due to some form of infection. Normally the infection is inhaled into the lungs but on rarer occasions it can come from an infection that is present elsewhere in the body.

Pneumonia tends to affect the microscopic air sacs in the lungs known as the alveoli. Normally these tiny sacs are filled with air. This warm, moist environment within the lungs is of course ideal for bacteria and other microbes to grow. As the micro-organisms begin to multiply, the alveoli become filled with fluid and pus. The exchange of air that takes place in these tiny air sacs is hampered and breathing becomes more difficult. The body's defence system responds by the white blood cells attacking the invading organisms. This causes inflammation - a normal response to infection.

For previously healthy people, most will recover fully from pneumonia. It tends to be more dangerous when it develops in people who already have an illness, very young children/babies and the frail elderly. In fact pneumonia is often the condition that develops when people are seriously ill. It can either be the primary or the secondary cause of death.

Types of pneumonia

Pneumonia is different from bronchitis - which is an inflammation of the large tubular airways, called the bronchi, leading to the lungs. However, the two conditions often occur together and this is called - bronchopneumonia.

There are various reasons for infections leading to pneumonia. The most common as given by the NHS (National Health Service) UK are:

• Bacterial pneumonia
• Viral pneumonia
• Aspiration pneumonia
• Fungal pneumonia

Bacterial Pneumonia

The most common bacteria to cause pneumonia is Streptococcus pneumoniae. It is also often known as - pneumococcal pneumonia. There are more than 90 separate strains of this particular bacteria and they enter the body through the nose or mouth.

Other organisms that can also cause pneumonia, but much less common are:

• Haemophilus influenzae
• Staphylococcus aureus
• There is also the Legionella pneumophila that causes the well known 'Legionnaire's Disease' which is a form of pneumonia.

Viral pneumonia

Viral pneumonia tends to be much more common in children than in adults. The most likely cause for this type of pneumonia comes from RSV (respiratory syncytial virus) or on rare occasions either the A or B flu virus.

Aspiration pneumonia

This type of pneumonia is caused by the inhalation of a foreign object or substance into the lungs. These often take the form of vomit, smoke, chemicals and small objects such as peanuts.

Fungal pneumonia

In the UK this form of pneumonia is very rare and tends to only affect people who have weak immune systems due to another illness. However, healthy people who travel abroad to countries such as Africa, Mexico, and South America may contract this form of pneumonia. There are also some regions in the USA where the fungi causing pneumonia can be found.

One of the best-known fungi that may cause pneumonia is histoplasmosis.

The signs and symptoms of pneumonia are varied. However, like any illness, some people may only experience one or two of the signs while others will have more.

Main signs and symptoms

As we have already seen the most common form is bacterial pneumonia and the symptoms listed below are for this type:

• Loss of appetite.
• Heartbeat increases rapidly.
• Pains in the chest.
• Some people also experience - headaches, nausea, joint/muscle pain.
• Fever with sweating/shivering bouts and generally feeling unwell.
• Coughing - this usually starts off as a dry cough but after a couple of days sputum is produced. This is usually yellowish in colour and can have blood staining as well. With some people the sputum is more rust coloured.
• Breathing becomes more difficult - you will usually notice the person breathing much more quickly than normal but the breaths are shallower. Breathing is affected in this way not only due to the infection, but because it might be painful to breath in deeply.
• People may have a blue tinge around the mouth and fingernails. This is due to the reduced amount of oxygen getting into the body. The body will reserve what oxygen it is getting for the vital organs and to fight the infection. Therefore, non-essential areas will receive less oxygen so making them blue.
• There can be a wheezing noise when breathing.
• Particularly in elderly people they become very confused.
• People who develop cold sores is a sign that the immune system is not coping and the herpes virus (cold sores) is able to develop.

Pleurisy

A double membrane called the pleura - a layer of protective tissue - covers the inside of the chest wall and lungs. There is a minute space between the double membrane known as the pleural cavity. This membrane secretes a fluid that lies in this cavity. This fluid prevents friction both between each lung and the surrounding structures of the body such as the chest wall.

When this protective layer becomes inflamed then this is what is known as pleurisy - sometimes it may be called pleuritis. Pleurisy is nearly always caused by another condition - normally a virus such as flu. With some people it's caused by pneumonia. In rare cases pleurisy can be caused by clots that interfere with the flow of blood in the lungs or lung cancer as well as a few other medical conditions.

With pleurisy the lubricating fluid that the membrane releases becomes clogged and sticky. This causes the two layers to rub together causing friction - making breathing painful and difficult

The main treatment for pleurisy is giving pain relief usually in the form of an anti-inflammatory and treating the underlying cause - for example if you have an infection and/or pneumonia. If pleurisy is caused by a virus, then in healthy people, the body usually kills this off within a few days and the pleural membrane returns to normal.

One interesting aspect about pleurisy - and no one is sure why this works - but lying down on the side where it's most painful can actually relieve the pain. It could be that the weight of the body reduces the friction being caused by the inflamed and dried pleura.

Symptoms

• The most common symptom is an extremely sharp pain when breathing and coughing. The pain is usually more severe when breathing in. The area where the pain is felt will depend on the location of the inflammation.
• However, if you have some form of infection in addition to pleurisy then you will also experience the signs and symptoms associated with that condition.

I hope this article has been useful in giving you more information about pneumonia and pleurisy. However, as always, this article is not a substitute for professional medical advice. If you are experiencing any of the signs described here then speak to your doctor as soon as possible.