Understanding Pneumonia And Pleurisy


Pneumonia definition

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 hub will shed some light on this ailment and give a clearer understanding of what's involved.

The lungs showing the smaller structures such as the alveoli.
The lungs showing the smaller structures such as the alveoli. | Source
Pneumonia can affect either one lung or both. When both lungs are affected this is called double pneumonia.
Pneumonia can affect either one lung or both. When both lungs are affected this is called double pneumonia. | Source
The alveoli of the lungs, showing both inside and outside the structure.
The alveoli of the lungs, showing both inside and outside the structure. | Source

What is pneumonia and its causes?

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 (respitory 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 fungus that may cause pneumonia is histoplasmosis.

Signs and symptoms of pneumonia

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.


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.


  • 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 hub 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 in the article then speak to your doctor as soon as possible.

© 2013 Helen Murphy Howell

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Comments 12 comments

Frank Atanacio profile image

Frank Atanacio 3 years ago from Shelton

It is so uncanny how you make this medi-hub easy to read and follow.. this is your nitch..:) voted useful and awesome and up

Sneha Sunny profile image

Sneha Sunny 3 years ago from India

You explained pneumonia in such a simple way. Really enjoyed reading your hub.

Thank you for sharing! :)

Voted up!

Gypsy Willow profile image

Gypsy Willow 3 years ago from Lake Tahoe Nevada USA , Wales UK and Taupo New Zealand

Thank you for a useful hub. Having experienced both conditions it is good to know the cause and the treatments. I remember the pain of pleurisy made laughing intolerable. Not good!

Seeker7 profile image

Seeker7 3 years ago from Fife, Scotland Author

Hi Frank - I have to say that you've really made my day with your wonderful comment. I've thought a little about whether or not writing easy to understand medical articles could be my nitch? So it's 'uncanny' as well that you've mentioned it - thank you a thousand times!!

Seeker7 profile image

Seeker7 3 years ago from Fife, Scotland Author

Hi Sneha Sunny - many thanks for stopping by and glad that you enjoyed the hub! Thank you as well for the vote up and share - greatly appreciated, thank you!

Seeker7 profile image

Seeker7 3 years ago from Fife, Scotland Author

HI Gypsy Willow, many thanks for stopping by and glad that you found the hub useful.

Thankfully, I've never had pleurisy or pneumonia, the closest I came to pain when breathing in was a torn muscle between the ribs and that was painful enough, so I can imagine how awful the pain of pleurisy would be. And yes, laughing is absolutely 'intolerable' and it doesn't help when you have a practical joker in the family who makes you laugh all the time!!

Gypsy Rose Lee profile image

Gypsy Rose Lee 3 years ago from Riga, Latvia

Voted up and interesting. You always provide much needed and useful information. My husband's mother got pneumonia a number of years ago. Then something tragic happened. They got all the water out of her lungs, the pneumonia was gone and the water returned. She had a cancerous growth on her pleura. That was in December of 2003. The year began with hospital visits to pull off water so she could breathe. Came toward the end of March and she was gone. It all happened so fast that I was in shock. I believe this was all a result of her having been struck by a car two years before and her whole right side was black and blue. Passing this on.

Seeker7 profile image

Seeker7 3 years ago from Fife, Scotland Author

Hi Rasma, lovely to hear from you as always and glad that you enjoyed the hub.

How awful for your Mum-in-law! The problem with fluid on the lung - apart from the fact that you have the horrible and frightening sensation of drowning - is that bacteria love the warm moist environment that this fluid provides for them. In addition to having the tumour her immune system would have also been low. Poor lady! And yes, it would be a huge shock, especially as people can deteriorate so quickly. I also agree with you that accidents often seem to be a trigger for more medical issues afterwards and then it can spiral out of control. As with your Mum, a nursing assistant that I knew a little from one of the hospitals I worked in, lost her husband when he was relatively young. He was also quite fit until he fell off a ladder at a building site, causing extensive knee damage. Well he seemed to recover from this, only to discover that a few months later, in the same knee, a tumour had developed. Only a few weeks after this he went into kidney failure - ? cause - and died not long after. So yes, it is a shock when people we love and care about are with us one minute full of life and the next they are no longer here!

Nell Rose profile image

Nell Rose 3 years ago from England

Fascinating reading seeker, and something I know quite well as I had Pneumonia as a child along with a collapsed lung. I was in hospital for six weeks, I never knew the details though, I just remember the pain and panic of not being able to breath. Great information, and voted up! nell

Seeker7 profile image

Seeker7 3 years ago from Fife, Scotland Author

Hi Nell, lovely to hear from you as always.

Glad that you enjoyed the hub but that's awful having pneumonia as a child. Also a collapsed lung - was this a pneumothorax? It sounds like it and it's extremely painful for an adult, never mind a poor wee lass, how awful for you! It's not surprising that the memory has stayed with you, I don't think anyone would forget the experience in a hurry!

old albion profile image

old albion 2 years ago from Lancashire. England.

Hi Helen. First class as usual. Your explanations are easy to understand and so informative.

voted up and all.


Seeker7 profile image

Seeker7 2 years ago from Fife, Scotland Author

Hi Graham, firstly huge apologies for taking so long to reply. My Dad has been unwell for a number of months now and I'm not on Hub Pages all that often at the moment. Hopefully this will change soon. Hope things are well with you and glad you enjoyed the hub.

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