Pneumonia

Causes of pneumonia

Pneumonia has many different causes. Many different germs can cause pneumonia, including bacteria, viruses, and fungi. You can also get it from breathing in (aspirating) food, liquid, chemicals and dust.

If you have pneumonia caused by a virus it is called viral pneumonia. Many different viruses can cause viral pneumonia, including the flu (influenza) and RSV (respiratory syncytial virus), a virus that is common in children. Viral pneumonia is usually less serious than bacterial pneumonia.

Viral pneumonia can be life threatening in:

• seniors and infants
• people who have a weak immune system from diseases like chronic lung disease, HIV, cancer and diabetes
• pregnant women

If you have pneumonia caused by bacteria it is called bacteria pneumonia. The most common type of bacterial pneumonia is Streptococcus pneumoniae (pneumococcus). Other bacteria that cause pneumonia include: mycoplasma pneumoniae, chlamydia pneumoniae and legionella pneumophila.

Bacterial pneumonia usually affects an entire lobe of the lung; doctors call this lobar pneumonia. People of any age can get it.

Other types of pneumonia include aspiration pneumonia. You can get aspiration pneumonia if you breathe (aspirate) something into your lungs, for example vomit, food or dust. Vomit is the most common cause of aspiration pneumonia. This can happen when people are unconscious or semi-conscious (knocked out) because of a stroke, accident or alcohol or drug overdose. Other things that can cause aspiration pneumonia include:

• liquid (for example, water)
• dust
• fungus

Other types of pneumonia can be caused by Pneumocystis jiroveci, a type of fungus commonly found in the environment. It can cause pneumonia in people with weak immune systems. It is most common in people with HIV/AIDS, diabetes, sickle cell and lung disease, and in people whose immune systems are weak from taking cancer treatment. Healthy people rarely get sick from breathing in the Pneumocystis jiroveci fungus.

If you have a weak immune system because of a chronic disease (for example, lung disease or HIV) and you get a cough, fever and/or shortness of breath, call your doctor.

Risk factors that increase your chances of getting pneumonia include:

• Chronic lung disease (COPD, asthma, cystic fibrosis)
• Cigarette smoking
• Dementia, stroke, brain injury, cerebral palsy, or other brain disorders
• Immune system problem (during cancer treatment, or due to HIV/AIDS, organ transplant or other diseases)
• Other serious illnesses, such as heart disease, liver cirrhosis, or diabetes mellitus
• Recent surgery or trauma
• Surgery to treat cancer of the mouth, throat, or neck

Signs and symptoms of pneumonia

The signs and symptoms of pneumonia can range from mild to serious. It depends on your age and what type of pneumonia you have. Some of the most common symptoms include:

• fever
• cough
• yellow-green phlegm (mucus)
• shortness of breath
• feeling very tired and unwell
• chest pain

If you have these symptoms it is important to go to your doctor right away.

Preventing pneumonia

There are vaccines available to prevent pneumonia caused by Streptococcus pneumoniae. Vaccination is especially important for those at high risk of serious illness or death from pneumonia. It is also important to stay up to date on vaccines for other respiratory infections that can lead to pneumonia.

Pneumonia vaccines are part of routine child immunizations in Canada. Adults 65 years of age and older and those under 65 with risk factors for serious illness should also be vaccinated. Depending on the type of vaccine received previously, some people who have been vaccinated my require a second dose of a different type of vaccine that protects against more strains of pneumonia bacteria.

Not smoking is one of the best things to do to help prevent pneumonia. People who smoke are at a higher risk of getting pneumonia and children whose parents smoke are at a higher risk for pneumonia.

There are other things you can do to reduce your risk of getting pneumonia:

• Wash your hands properly and often 
• Throw away used tissues
• Don’t share cups or eating utensils with people who are sick
• Stay away from people who are sick

 

Treating pneumonia

The main treatment for bacterial pneumonia is antibiotics, rest and drinking lots of water. Most people with pneumonia will manage their condition at home with medication from their physician.  Some people with severe pneumonia will need to go to the hospital to have additional support of oxygen, and medication through an IV.

People who have been admitted to the hospital with other medical conditions and develop pneumonia may become very ill and may need very powerful antibiotics.

If you are prescribed antibiotics it is important to take the medicine as your doctor prescribes, even if you start to feel better. Do not take cough medicine or cold medicine unless your doctor says it is okay.

Antibiotics do not treat viral pneumonia. Some of the treatment of viral pneumonia may include drinking lots of fluids, corticosteroid medicine, oxygen and rest.   

If you have a milder pneumonia, you will usually begin to feel better within a few days or a week. If you have severe pneumonia, where you spend time in the hospital you may take a number of weeks to feel better.

Information and resources from our partners at Immunize Canada