Pneumonia: Causes, Symptoms, and Treatment

What are the most common causes of pneumonia?

Pneumonia can develop as a complication of a viral infection like the common cold, flu, or COVID-19. In these cases, instead of being limited to the upper respiratory tract (nose, sinuses, larynx), the virus manages to reach the deeper structures of the lungs. In young children, pneumonia is often caused by the respiratory syncytial virus (RSV).

Pneumonia can also be caused by bacteria, for example, a pneumococcal bacterium. These types of pneumonia tend to be more severe than viral pneumonia. Bacterial pneumonia can also be a complication of a viral infection. This is known as bacterial superinfection.

People with HIV are at greater risk of contracting pneumonia caused by micro-organisms called mycoplasma.

Pneumonia can also be caused by accidentally breathing in a substance that irritates the lungs. A typical example might be the aspiration of food particles in a person who has trouble swallowing due to illness or intoxication.

Who is most at risk of developing pneumonia?

Certain categories of people are more likely to develop pneumonia, due primarily to a less efficient immune system or reduced lung function.

• Young children
• Older people
• People whose immune system has been weakened by disease, e.g., HIV or cancer, or by a medical treatment, e.g., an organ transplant
• People with chronic lung disease such as chronic obstructive pulmonary disease (chronic bronchitis, emphysema), and severe asthma

What are the symptoms of pneumonia?

The symptoms of pneumonia vary depending on the severity of the infection, the type of pathogen, and the person's overall health. A cough is almost always present.

Possible Symptoms:

• Severe cough, that is productive (yellow or green mucus) if it’s a bacterial infection, but dry if it’s caused by a virus
• Chills (especially with bacterial infection)
• Fever that is high when it’s a bacterial infection (up to 40,5 °C), or moderate when it’s a viral infection (up to 39 °C)
• Shortness of breath, rapid breathing or trouble breathing
• Chest pain that gets worse when you breathe deeply or cough, especially if it’s a bacterial infection
• Intense fatigue
• Confusion or disorientation in older people
• Nausea, vomiting, or diarrhea (mycoplasma pneumonia)

Symptoms of pneumonia are usually severe enough to prevent a person from going about their usual activities. However, sometimes pneumonia causes only mild symptoms, so that the person is able to carry on their activities. This is sometimes referred to as “walking pneumonia” or “atypical pneumonia.”

How do you know if you have pneumonia?

Pneumonia is diagnosed based on symptoms, medical history, physical examination, and the results of chest X-rays. Sometimes, blood or sputum tests are done to identify the exact cause of the infection.

Can pneumonia be prevented?

Like with common respiratory infections, the best defence is regular handwashing and avoiding close contact with sick people, as they can expel droplets containing the virus or bacteria when they cough or sneeze.

Vaccination is another way to reduce the risk of developing pneumonia. In addition to certain vaccines administered during childhood, the following vaccines can be given to reduce the risk of certain types of pneumonia:

• Vaccine against pneumococcal pneumonia for older people and those with certain chronic diseases
• Yearly flu shots for all Canadians
• COVID-19 shot, according to public health recommendations

Your pharmacist can help determine which vaccines you need, and your eligibility for free vaccination programs in your province. Most pharmacies offer vaccine administration services. 

How is pneumonia treated?

The treatment for pneumonia depends on the underlying cause of the infection and the severity of your symptoms.

Viral pneumonia is generally treated with support measures such as rest, hydration, and treatment of symptoms with over-the-counter medication, for example, acetaminophen to reduce fever.

Where pneumonia is caused by bacteria, antibiotics will be prescribed together with support measures to relieve symptoms.

In severe cases, such as when breathing becomes very difficult, or when health is threatened because of other illnesses, hospitalization may be necessary.

It's worth noting that coughing is the symptom that lasts the longest. It is not uncommon for it to persist for several days or even weeks after the other symptoms have disappeared.

Your pharmacist is there for you!

Got questions about how pneumonia is treated or the services available at your pharmacy to reduce the risk of pneumonia? Speak to your pharmacist! They will be able to answer your questions, provide advice on ways to relieve your symptoms, or refer you to the appropriate medical resources as needed.