Pneumonia: Symptoms, Causes, Risks, Complications, Diagnosis, Treatment and Prevention

Illustration of Pneumonia


The respiratory system is a very important part of the body. It is responsible for the transfer of oxygen into the bloodstream and the extraction of waste produces particularly carbon dioxide from the blood. This way, oxygen, which is vital for life, is carried to the different cells in the body.

However, just like any part of the body, the respiratory system, particularly the lungs, may have various diseases. The most common conditions affecting the lungs is an infection. When there is an infection in the lungs, it may alter one’s respiration, breathing, and overall health.

Pneumonia is one of the most common infections in the lungs. Pneumonia is an infection in one or both lungs that can be caused by bacteria, viruses, and fungi. However, the most common type of pneumonia is the one caused by bacteria.

The condition may cause inflammation in the alveoli or air sacs in the lungs, making it hard to breathe. Often, these air sacs will be filled with pus or fluid. Pneumonia is a life-threatening condition if it is not treated immediately, especially to high-risk groups like old adults, babies, children, pregnant women and those with immunosuppression.

According to the World Health Organization (WHO), about 16 percent of all deaths among children under five years old are caused by pneumonia. The lung disease killed about 920,136 children in 2015 alone.

Pneumonia can be treated if it’s detected early and it can be prevented through immunization, adequate nutrition and dealing with environmental factors.


The symptoms of pneumonia can develop abruptly within 24 to hours and in some cases, may develop slowly over several days. Moreover, the signs and symptoms of pneumonia may also vary from mild to severe, depending on various factors such as the type of pathogen, the overall health of the patient and the age of the patient.

The common symptoms include:

  • A cough (Dry or productive with thick yellow, green or blood-tinged mucus or phlegm)
  • Increased heart rate
  • Shortness of breath or difficulty of breathing with breathlessness even when resting
  • Feeling unwell
  • Fever
  • Sweating
  • Chills
  • Anorexia or loss of appetite
  • Chest pain, worse when coughing

Less common symptoms include:

  • Nausea and vomiting
  • Hemoptysis or coughing up blood
  • Wheezing
  • Muscle and joint pains
  • Feeling disoriented or confused


The air that people breathe is sometimes full of germs and pathogens. However, the body prevents these germs from infecting the lungs. Sometimes, these pathogens can be strong enough that they can overpower the immune system, leading to a respiratory infection.

Pneumonia is usually the result of pneumococcal infection, which is caused by the bacteria called Streptococcus pneumoniae. However, other pathogens may also result in this lung infection.

Community-acquired pneumonia

Community-acquired pneumonia is the most common type of pneumonia and it happens outside healthcare facilities and hospitals. Here are the major causes of CAP:

Bacteria – The common cause of bacterial pneumonia is Streptococcus pneumonia. It usually develops after a cold or flu.

Fungi – Fungi may also cause pneumonia. This usually attacks people who have weakened immune systems and those who have inhaled huge doses of the microorganism.

Viruses – Viruses may also cause pneumonia stemming from a cold or flu. These infections are common in children who are below five years old. Though this is rare, it may become very serious since there is no medicine for viruses.

Aspiration pneumonia

This type of pneumonia happens when the patient has breathed in vomit or a foreign object that becomes clogged in the airways.

Hospital-acquired pneumonia

This type of pneumonia is acquired while being confined in the hospital. This is also called a secondary infection. Some people may develop pneumonia and this can be serious because the pathogen may become more resistant to antibiotics since the patient is already sick. Usually, those who are in intensive care units (ICU) are the ones affected by this infection.

Pneumonia can spread in various ways. Usually, the bacteria and viruses found in the throat or nose can infect the lungs if they are inhaled. For transmission, it can be transferred via air-borne droplets when the patient coughs or sneezes. In other cases, the disease can be spread through blood, particularly during and shortly after birth.

Risk Factors

Some individuals are at a higher risk of developing pneumonia. The risk factors are:

Age – Some people are susceptible to acquiring pneumonia because of their age.
Children who are two years old or younger and those who are 65 years or older are at an increased risk of having this lung disease.

Weakened immune system – People who have certain diseases that suppress the immune system may become more vulnerable to pneumonia. Diseases like human immunodeficiency virus (HIV), acquired immunodeficiency syndrome (AIDS), and those who have undergone organ transplant or chemotherapy are at risk.

Pregnant women – Pregnant women are at a higher risk of developing pneumonia and this may cause certain problems during pregnancy. It is better to have the disease treated early to prevent serious complications.

Being confined in the hospital – If the patient is hospitalized, there is a greater risk of acquiring pneumonia, particularly if he or she uses a machine to help in breathing like a mechanical ventilator.

Smoking – Smokers are at a higher risk of developing pneumonia because the chemicals in cigarette smoke damage the body’s natural defenses against pathogens that cause disease.

Chronic diseases – Certain chronic diseases involving the lungs may increase the risk of pneumonia including chronic obstructive pulmonary disease (COPD), heart disease or bronchial asthma.


Pneumonia is a life-threatening disease. It can be prevented and treated but even with treatment, some individuals may still experience some complications such as:

Bacteremia – This is a term to describe the presence of bacteria in the bloodstream.
This happens when the bacteria in the lungs enter the blood and spread the infection to the other organs. This is dangerous and could lead to multiple organ failures.

Sepsis or septicemia – This is a rare but life-threatening complication. It happens when there is blood poisoning due to infection.

Pleurisy – This condition happens when the thin linings between the lungs and rib cage, which is called pleura become inflamed. This condition may lead to respiratory failure if it’s not treated immediately.

Pleural effusion – This is a term for describing the fluid accumulation around the lungs. Pneumonia may lead to fluid buildup in the pleura.

The difficulty of breathing – In some cases, people with pneumonia may feel the difficulty of breathing. This is serious and needs hospitalization, especially if the oxygen levels in the body decreases to dangerous levels.

Lung abscess – A lung abscess happens if the pus forms in the cavity of the lungs.
An abscess is typically treated with antibiotics, but this can cause serious conditions if it’s not treated immediately.


The doctor needs to ask questions about the medical history of the patient. Also, a complete medical examination is needed to diagnose if the condition is pneumonia. The doctor may also listen to the lung sounds through the use of a stethoscope to assess for abnormal lung sounds. A person with pneumonia would manifest bubbling or crackling sounds.

Here are the other diagnostic tests recommended:

Blood test – The doctor will request for a blood test, specifically a complete blood count (CBC) to determine if there is an ongoing infection in the body. However, this test would not be able to identify the cause of the infection.

Chest X-ray – A chest X-ray is also requested to show the images of the lungs to determine if there is pneumonia. In some cases, however, further tests are needed for confirmation.

Sputum test – A sputum test is used to determine the cause of the infection in the lungs. This test can also determine the type of drug to use.

Pulse oximetry – A pulse oximetry will determine the oxygen levels in the blood. This will determine the lungs are moving enough oxygen throughout the body.

Bronchoscopy – This test is used to look at the airways and with the use of a camera, it takes footages to determine if the linings are inflamed or infected.

CT-scan – This imaging test is more accurate and detailed than a chest X-ray. It takes clearer photos and cross-sectional images of the organ.

Fluid sample – A fluid sample is used to determine if the patient has pleural effusion or fluid accumulation in the pleural space in the chest.


Pneumonia can be treated and prevented. However, it is important to note that this condition can become life-threatening if it’s not managed early on. In most cases, this condition is treated at home with medication. However, more severe cases might need hospitalization.

Here are the treatment options for pneumonia:



The medications used to treat bacterial pneumonia are antibiotics. It may take some time to determine the type of bacteria causing the infection. A sputum test is also important to determine which specific antibiotic will be used to treat the condition.

Cough medicine

Since pneumonia will cause a cough, it is important to manage this symptom to give the patient ample time to rest. Taking cough medicines will relieve the symptom.

Antipyretic or fever reducers and pain relievers

These medicines will treat fever and discomfort. Pain relievers may also help reduce muscle and joint pains.

Home remedies

These home remedies may help the patient recover more quickly and decrease the risk of complications.

  • Stay hydrated by drinking plenty of fluids, particularly water. This can also help loosen the mucus in the lungs.
  • Get plenty of rest and do not go to work or school when you’re sick. This you’re your body will get the adequate rest needed for faster recovery.
  • Take medicine properly and never stop the antibiotics without completing its dose.
    This will prevent the occurrence of drug resistance.


It is important to note that prevention is better than cure. Here are ways to prevent having pneumonia:

  • There is a vaccine intended to reduce the risk of the development of pneumonia.
    Ask your doctor about getting the shots.
  • Children, especially those who are below 5 years old should get their vaccines, too.
    They are at a higher risk of complications when they get pneumonia. So, preventing acquiring the disease is essential.
  • Avoid smoking since the chemicals in cigarette smoke reduce the body’s natural defenses against respiratory infections. Moreover, smoking also damages the lining of the lungs, making it prone to certain diseases.
  • Practice good hygiene by always washing the hands or using an alcohol-based hand sanitizer. It is important to also teach the kids about handwashing.
  • Boost the immune system by getting enough rest and sleep, eating healthy foods especially those that are high in vitamin C and drinking adequate amounts of water.