What is pneumonia (overview)?

Pneumonia is an infection caused by fungi, bacteria or viruses, that occurs in one or both lungs. A build-up of fluid or pus causes inflammation in the lung’s air sacs (known as alveoli) and makes it difficult for a sufferer to breathe.

An infection usually starts when you breathe germs (bacteria, fungi or virus) into your lungs. Often pneumonia is brought on after suffering a cold or flu. With an already weakened immune system such illnesses make it more difficult for your lungs to fight further infection, and thus worsen and develop pneumonia. Chronic conditions such as asthma, cancer, diabetes or heart disease can also make you more easily susceptible to developing an infection causing pneumonia.

Signs of pneumonia range from mild to life-threatening and include running a high fever, coughing and trouble breathing. In mild cases, pneumonia can generally be treated with sufficient home care, with symptoms clearing up completely within 2 to 3 weeks.

A severe infection is considered a medical emergency. Medical professionals will assess the severity of your symptoms by taking into consideration the cause of your inflammation, the type of organism which is likely to have caused the infection, your overall health and age.

What to expect

How  a pneumonia infection affects the human body.

Symptoms of pneumonia tend to come about slower than those of flu, but faster than the common cold. Pneumonia is often a complication of these viral infections where the same organism is the cause of commonly experienced symptoms.

Symptoms for the common cold only affect the upper respiratory tract (nose and throat), whereas the flu virus reaches the lungs, affecting the respiratory system (nose, throat, bronchial tubes and lungs). In the case of pneumonia, flu-like symptoms worsen due to the presence of bacteria, fungi or virus.

Symptoms of pneumonia

Symptoms of bacterial pneumonia in individuals younger than 65 and in generally good health most often begin during or after an upper respiratory infection, such as cold or flu.

Non-bacterial pneumonia symptoms come on gradually and are often milder than those caused by bacterial infection. Many aren’t aware of their infection until symptoms start to appear and they begin to feel ill.

Common symptoms for both bacterial and non-bacterial pneumonia include:

  • Cough: A cough will likely include mucus (sputum) that is forced up from the lungs. This mucus can have a yellow or green colour, sometimes tinged with blood.
  • Fever up to [celcius:38] or higher
  • Shortness of breath or fast-paced breathing (especially when moving around).
  • Shaking and ‘the chills’
  • Chest pain which worsens when you cough or take in a breath. Pain can be sharp and feeling ‘stabbing’ in nature.
  • Rapid heartbeat
  • Weakness and fatigue
  • Nausea and vomiting
  • Diarrhoea
  • Lack of appetite
  • Profuse sweating
  • Blue lips and fingernails
  • Confusion or delirium: This is mostly experienced in older people.

Symptoms in children and babies

Symptoms in little ones may be subtler and are dependent on age. Infants younger than 1 month, in particular, can experience little or no energy, poor feeding, grunting and a high fever.

Children often experience the same symptoms as adults. Your doctor will be mindful of other conditions with similar symptoms as pneumonia, such as bronchitis, COPD (chronic obstructive pulmonary disease - note: COPD is not found in children), and tuberculosis, before making their diagnosis.

General things to look out for in babies and children are:

  • Laboured or rapid breathing (more than 45 breaths a minute)
  • A high fever
  • Cough
  • Wheezing
  • Blue skin, lips and fingertips and nails
  • Difficulties with feeding (this applies mostly to babies)

Symptoms in older adults

Seniors can experience different, fewer or even milder symptoms. It is common for an older adult to not experience a high fever or cough without the presence of mucus. One of the most telling signs of pneumonia in older adults is whether there is a definitive change in how clearly they are able to think. Along with signs of confusion or delirium, a lung disease which worsens is also more common in older adults diagnosed with the infection.

Factors to consider

Causes and types of pneumonia

Diagram comparison of healthy respiratory function and pneumonia infection.

Pneumonia is caused by viruses, and bacteria, and in some cases a fungus or parasite. Pneumonia is however, very rarely brought on by a parasite or other organism. In the vast majority of cases, the bacteria or virus causing the infection is identified as streptococcus pneumoniae.

Pneumonia can also be caused by a bacteria-like organism called mycoplasma pneumoniae. Mycoplasma pneumonia is also known as “walking pneumonia” or atypical pneumonia with milder symptoms. A common form of pneumonia, especially among people under the age of 40, symptoms are easily treated with antibiotics.

The flu virus, RSV (respiratory syncytial virus) and the human Rhinovirus can also cause pneumonia. RSV is a common viral infection experienced in childhood. Symptoms experienced include a runny nose, coughing and wheezing, and tends to clear easily with home care.

Sometimes RSV can worsen and develop into pneumonia or other breathing difficulties such as bronchitis, which will require medical treatment and / or hospital care.

Those with impaired or weaker immune systems are at higher risk of pneumonia. Some types of fungi, such as Pneumocystis jiroveci (previously known as Pneumocystis carinii or PCP) have been known to cause pneumonia in people diagnosed with HIV / AIDS and tuberculosis. Some doctors may recommend an HIV test if it is suspected that Pneumocystis jiroveci is the cause of a pneumonia infection as this can often be one of the first signs of the disease.

The most common types of pneumonia are:

  • Bacterial: This type of pneumonia affects anyone and at any age. The infection develops either on its own or following a round of serious cold or flu.  Bacteria that most cmmonly causes the infection is streptococcus pneumoniae. Other known bacteria that cause pneumonia are Haemophilus pneumoniae and Moraxella catarrhalis. Chlamydophila pneumonia or legionella pneumophila are atypical causes.
  • Viral: Respiratory viruses are often the cause of an infection, especially among seniors and young children. In many cases, pneumonia is not severe and lasts a short time. A severe case of the flu that develops into pneumonia may, however, cause viral pneumonia which can be severe and even life-threatening. Viral pneumonia is particularly harmful to pregnant women and those with heart and lung conditions.
  • Mycoplasma: These organisms are not classified as viruses or bacteria, although they have traits common to both. Mycoplasmas generally cause milder cases of pneumonia and are the smallest agents of the condition affecting human beings. As a cause, mycoplasmasare most common among older children and young adults.

What happens

Once infected with a pneumonia-causing organism, symptoms show up within 1 to 3 days. Sometimes symptoms can take up to around 7 to ten days to appear. How long the infection lasts for, as well as its severity, depends on the following factors:

  • Your overall health and age
  • Whether the infection is caused by a virus or bacteria (viral pneumonia is usually less severe than a bacterial infection).
  • How quickly the infection is treated (the sooner, the better).
  • Whether you have a healthy or impaired immune system.

If the infection occurs in an individual that is generally healthy, symptoms can be reasonably mild and easily treated over a period of 2 to 3 weeks. Infections in older people, as well as those who have other known health problems, can take between 6 and 8 weeks to clear completely.

Where a milder case of pneumonia is diagnosed, it may not be necessary to be admitted for hospital care. Older adults are, however, almost always treated in hospital and tend to stay longer than younger people with stronger immune systems and no other medical concerns to recover. Older people are at higher risk and often tend to develop other medical concerns which need medical treatment.

Risk factors and complications

Factors which may make you more high risk or could cause complications include:

  • Smoking
  • Other medical conditions
  • Younger than 1 year or older than 65
  • Have a weak immune system
  • Take proton pump inhibitors to reduce the amount of stomach acid your body produces
  • Excessive alcohol consumption / have an alcohol use problem
  • Recently had a bout of cold or flu
  • If you have been treated in hospital for another medical health concern within the last 3 months
  • If you had your spleen removed or have an impaired spleen 

Treatment Procedures – Remedies and Relief

When should you see a doctor?

If cold and flu symptoms do not clear up within the expected timeframe, and appear to worsen, it is best to consult your doctor as soon as possible. Although not all cases of pneumonia need to be treated in hospital, the infection must be diagnosed and treated by a medical professional as soon as possible.

Signs that require immediate medical assistance include:

  • A crushing or squeezing chest pain that increases in intensity, especially when you cough.
  • Trouble breathing – this can be shallow, fast-paced breathing, shortness of breath or wheezing.
  • Coughing up large amounts of blood or rust-coloured mucus. You will also need to see your doctor as soon as possible if your cough frequently brings up yellow or green mucus from the lungs for more than 2 days, occurs with a high fever, vomit frequently or persists for longer than 4 weeks.
  • Dizziness and feeling faint, particularly when sitting up or standing

Diagnosis and tests

Your doctor will assess your symptoms as well as their severity at your consultation. This assessment will likely include a series of questions:

  • What symptoms are you experiencing and how long ago did they start?
  • Have you been travelling at all recently?
  • Have you been exposed to anyone who has been ill?
  • Do you have any past or current medical concerns or problems?
  • Are you taking any medications?
  • Do you smoke? Have you ever smoked? For how long did you smoke?
  • Have you had any vaccinations or other illnesses recently?

Chest X-ray showing pneumonia infection.Your doctor will then conduct a physical exam to better assess and diagnose your symptoms. Things he or she will look out for include crackling, wheezing orunusual sounds in the chest, particularly when you take a breath.

Your doctor may request a chest X-ray to help determine whether you have an infection in your lungs. A chest X-ray will not likely show your type of pneumonia (for instance, viral or bacterial). This will be determined through blood tests. Blood tests will also be necessary to assess if the infection is in your bloodstream.

Additional tests

Depending on the findings of the initial assessments and tests, your doctor may feel it necessary for the following additional tests to diagnose your illness:

  • A CT scan: Similar to an X-ray, the scan will provide a more precise picture which is highly detailed.
  • A sputum test: Mucus that is coughed up is examined to determine the type of pneumonia.
  • Fluid samples: Your doctor will take a fluid sample to determine whether an infection is viral or bacterial if it is noted that there is fluid in the pleural space (the space between the inside of your chest cavity and the tissue covering the outside of your lungs). 
  • A pulse oximetry test: A small sensor is attached to the tip of your fingerand measures the level of oxygen blood saturation. Pneumonia normally prevents normal oxygenation of the blood.
  • A bronchoscopy: If a course of antibiotics fail to treat your pneumonia, your doctor may suggest a bronchoscopy to see the airways inside your lungs and determine whether or not any blockages are inhibiting treatment of your pneumonia.

Treatments and medications

Typical treatment recommended by your doctor will include prescribed medications, as well as some follow-up care. Once you have recovered from your infection, your doctor may request a chest X-ray to ensure that your pneumonia has been 100% successfully cleared.

Bacterial pneumonia will be treated with antibiotics that should be taken as recommended by your doctor. Antibiotics have a high cure rate for treating pneumonia. If you stop taking your course of antibiotics before treatment is complete, you do run the risk of falling ill again. Most people will begin to feel better and notice improvement of their symptoms within 1 to 3 days. The number of days you will be required to take antibiotics will depend on your general health, the severity of your infection, as well as the type of antibiotic your doctor is prescribing.

Viral pneumonia cannot be treated with antibiotics. Instead your doctor will recommend supportive care and sometimes antiviral medications to treat your infection. Symptoms will usually clear up within 1 to 3 weeks.

You may need to be hospitalised if:

  • You are undergoing treatment but are not getting better or showing signs of improvement.
  • You are older than 65.
  • Have other health problems or chronic conditions causing complications.
  • You are unable to tell if your symptoms are worsening or cannot care for yourself.
  • Have a severe illness that reduces the amount of oxygen allowed to reach your bodily tissues.
  • Experience chest pain caused by pleurisy (inflammation of the lining of the lungs and the inability to cough up mucus to help clear out the lungs).
  • You are unable to eat or keep food down. In this instance, you will need intravenous treatment (take fluids through a vein).

In most mild cases where individuals are generally healthy and have strong immune systems, home care is possible. Prescribed medications, rest and fluids are usually all you need to recover from an infection. Sometimes lung problems and difficulties with breathing will require more treatment. In this case an inhaler or nebuliser will be recommended to help alleviate wheezing and shortness of breath symptoms.

In more severe cases you may need respiratory therapy to help remove mucus from the lungs. Therapy includes deep breathing exercises, postural drainage, incentive spirometry and chest physiotherapy. Oxygen therapy may also be necessary if your doctor feels that the cells of your body are not getting enough oxygen. Oxygen is given through a nasal tube or face mask, and using a tent that fits over a crib for a young child or baby.


How do you get pneumonia?

  • You may breathe or inhale infected air particles or bacteria into your lungs from your nose and throat. This can often happen while you sleep.
  • You can become infected during or after experiencing a viral upper respiratory illness such as cold or flu.
  • Pneumonia can develop as a complication of a viral illness, such as measles or chickenpox.
  • You may inhale or breathe large amounts of gastric juices, and even food from the stomach, as well as vomit into the lungs (this is known as aspiration pneumonia). It occurs when you already have a medical condition affecting your ability to swallow, or you experience a stroke or seizure.
  • You can also become infected in public areas frequented by people in your daily life. This is often referred to as ‘community-associated pneumonia’ and ‘healthcare associated acquired pneumonia’. The two are distinguished differently as bacteria causing the infection in hospitals may be different from those in the community, and likely require different treatment.

Is pneumonia contagious?

If the cause of your infection is viral or bacterial, you may spread the illness to other individuals during the contagious period. You may be contagious for several days to a week, but this period largely depends on what is causing your pneumonia and whether you seek appropriate treatment.

If you are being treated with antibiotics, you are usually not contagious and cannot spread the infection to others after at least a day of treatment.

Who should you see to diagnose pneumonia?

Health professionals who can diagnose and treat your symptoms include:

  • General practitioners (GPs)
  • Paediatricians
  • Infectious disease specialists
  • Specialists in lung diseases (pulmonologists)
  • Physician assistants
  • Nurse practitioners

Disclaimer - is for informational purposes only. It is not intended to diagnose or treat any condition or illness or act as a substitute for professional medical advice.