Healthy Living

What Causes Pneumonia?

What Causes Pneumonia?

Key Takeaways

Pneumonia is a lung infection that is caused by bacteria, viruses, or parasites. Moreover, pneumonia can develop in just one lobe of the right or left lung, the entire lung, or both of the lungs simultaneously. The primary characteristic of this lung disease is the inflammation of the air sacs or alveoli in your lungs. People with pneumonia can experience a difficulty in breathing due to the inflamed and fluid-filled or pus-filled air sacs.

Viruses account for approximately 50 percent of pneumonia cases that tend to be less severe compared to bacterial pneumonia. Pneumonia is still one of the leading causes of death in children who are under 5 years old worldwide.

The best prevention against pneumonia is vaccination. The lung infection can also be treated with antibiotics, antiviral drugs, or specific drug therapies. In some cases, based on the severity of the infection and the individual's condition, hospitalization may be necessary.

It is a critical ailment that can affect individuals at any age group. However, it poses more danger to the lives of infants, toddlers, very young children, as well as elderly people. Individuals with weak immune systems, including the elderly, and individuals who have health issues such as heart disease, diabetes, flu, or chronic lung diseases are more vulnerable to contracting pneumonia.

The fluids that leaked from the infected lungs shed dead cells, and these cells clog up the air sacs, which will make it difficult for the lungs to take in air and absorb oxygen. Without adequate oxygen, the normal functioning of the cells in the body will be negatively affected.

Causes of Pneumonia

Most of the time, people get pneumonia after inhaling infectious microorganisms into their lungs. However, the infection can also get to the lungs through your bloodstream or when it is being transported from a nearby infection in the body. The condition can also be triggered by a common cold or flu, which paves the way for the germs to access the air sacs.

Moreover, patients who stay for a longer time at hospitals due to surgery or other types of sickness can develop pneumonia. The reason is that when patients are immobile, they tend to have a shallow breathing and will not be able to cough properly, leading to a mucus buildup in their lungs, thereby making them more susceptible to bacterial infections.

Listed below are some of the microorganisms that can cause pneumonia:

  • Bacteria – bacterial pneumonia is characterized by a rust or green-colored phlegm. Although, anyone at any age can be affected, the most vulnerable groups are infants, the elderly, alcoholics, and patients who are recovering from a surgery or coping with other diseases.
  • Viruses – the symptoms of viral pneumonia are the same to that of a severe bout of flu. It is believed that half of reported pneumonia cases are due to viral infections.
  • Mycoplasma – the symptoms of this type of pneumonia can include a white phlegm, nausea, and vomiting. Pneumonia that is caused by mycoplasma organisms is generally mild. However, recovery takes longer compared to other types of pneumonia.

Risk Factors

The factors that put some people more at risk of developing pneumonia include:

  • babies, toddlers, and very young children
  • people who are above 65 years old
  • people who abuse alcohol
  • smokers
  • people who have chronic diseases such as heart failure, diabetes, or chronic obstructive pulmonary disease (COPD)
  • people who have weak immune systems

People who are 65 years old and above tend to have a weaker immunity to infections and are at higher risk of being infected by bacteria, viruses, and other harmful microorganisms. Due to a person's weak immune system, germs can infect the lungs and cause inflammation. In certain instances, the germs can multiply resulting in a lung infection.

The factors that can influence the development of low immunity include:

  • alcohol dependence
  • AIDS
  • serious illnesses
  • people who live in communities where the infection has spread

When an individual breathes, he or she will inhale air through the nose, which then passes through the windpipe, the bronchi, and then into the bronchioles. The bronchioles end in tiny sacs called alveoli, which are located within the tiny blood vessels called capillaries.

As we draw in air through our nose and mouth, these organs in our body are continually exposed to microorganisms such as bacteria, virus, and fungi. When an individual with weak immunity is exposed to a strong virus or bacteria, or to a very large number of microorganisms, he or she can get pneumonia. These microorganisms move into the alveoli and will keep growing in their number. When this happens, the body generates white blood cells (WBCs) to fight the infection. Thus, the alveoli get packed with white blood cells (WBCs), proteins, fluid, and red blood cells (RBCs), thereby getting inflamed. This entire process generally takes place in the first 24 hours of catching the infection. Due to the infection, fluid displaces some of the air in the lungs resulting in the swelling of the pleurae.

In a couple of days, small blood vessels that surround the alveoli swell up and blood seeps into the alveoli. The swollen lungs with blood will have a liver-like appearance. A few days later, the lungs will appear gray or brown in color, as the accumulated red blood cells (RBCs) break down. Finally, the structure of the lungs starts to return when the immune system begins to fight the infection. This period is called as the resolution stage. At this time, the individual may start coughing out discolored or bloody mucus called sputum, as a way to clear the lungs and allow air sac re-aeration.

Signs and Symptoms of Pneumonia

Usually, the initial signs of pneumonia show fever with a cough. Other signs and symptoms of the disease include:

  • a difficulty in breathing or shortness of breath
  • chest pain that fluctuates with breathing
  • headache or muscle pain
  • cyanosis (bluish discoloration of the skin around the mouth due to of lack of oxygen)
  • decreased appetite
  • fatigue or an overall feeling of being unwell

It is highly recommended that you consult your doctor if you experience the abovementioned signs and symptoms of pneumonia. Remember that pneumonia can be a life-threatening disease and its early detection and treatment can effectively prevent negative consequences.