Pneumonia – Causes, Symptoms, Treatments

What is Pneumonia?

Pneumonia is an infection that inflames the air sacs in one or both lungs. The air sacs may fill with fluid or pus (purulent material), causing cough with phlegm or pus, fever, chills, and difficulty breathing. Pneumonia can range in severity from mild to life-threatening and can be caused by a variety of organisms, including bacteria, viruses, and fungi. It can be acquired in community settings (community-acquired pneumonia) or in healthcare settings (healthcare-associated pneumonia).

Anyone can get pneumonia, but infants younger than age 2 and people over age 65 are at higher risk. This is because their immune systems might not be strong enough to fight off infection. You can get pneumonia in one or both lungs. You can also have it and not know it. Doctors call this walking pneumonia

Pneumonia is a very prevalent lung infection. In fact, it is a leading cause of hospitalization and death from infectious disease globally according to the World Health Organization. Every year, pneumonia claims the lives of an estimated 725,000 children under the age of 5, including around 190,000 newborns, who are particularly vulnerable to infection according to Unicef statistics. In the United States, pneumonia is a leading cause of hospitalization for adults. More than a million people in the United States are hospitalized with pneumonia each year.

Symptoms of Pneumonia

Pneumonia can indeed manifest with a wide range of symptoms, from mild and barely noticeable to very severe and requiring hospitalization. Here’s a breakdown of the spectrum of symptoms:

Common Symptoms:

• Cough: This is the most common symptom of pneumonia, and it can be productive (meaning it brings up mucus) or dry. The mucus coughed up may be green, yellow, or even bloody.
• Fever: A fever is another frequent symptom, although it may not always be present. In some cases, particularly with viral pneumonia, the fever may be low-grade.
• Difficulty Breathing (shortness of breath): This can range from mild shortness of breath to severe difficulty breathing that makes it hard to talk or lie down.
• Chest Pain: Sharp or stabbing chest pain that worsens with breathing or coughing is a common symptom of pneumonia.

Other Possible Symptoms:

• Fatigue: Feeling tired and run down is a general symptom of infection and can occur with pneumonia.
• Headache: Headaches can sometimes accompany pneumonia, especially with viral pneumonia.
• Loss of Appetite: Loss of appetite is another common symptom of infection and can occur with pneumonia.
• Nausea and Vomiting: These are more common in children with pneumonia but can also occur in adults.
• Confusion: This is more likely in older adults with pneumonia and can be a sign of low oxygen levels or dehydration.

Severity Variations:

The severity of symptoms can vary depending on the type of pneumonia, the person’s age and overall health, and the severity of the infection.

• Mild Pneumonia: In some cases, pneumonia may cause only mild symptoms, such as a low-grade fever, mild cough, and slight fatigue. This is sometimes referred to as “walking pneumonia” because people with these symptoms may still be able to go about their daily activities.
• Severe Pneumonia: Severe pneumonia can be life-threatening and requires immediate medical attention. Symptoms of severe pneumonia may include high fever, severe difficulty breathing, rapid breathing, chest pain that is constant or worsens with breathing or coughing, bluish skin or nail beds (cyanosis), confusion, and disorientation.

Older Adults:

It’s particularly important to be aware of the signs of pneumonia in older adults, as they may not present with the typical symptoms. Confusion, delirium, and changes in mental alertness can be prominent signs of pneumonia in this age group, even in the absence of a fever or cough.

Risk Factors for Pneumonia

Several factors can significantly increase a person’s risk of developing pneumonia. Age is one of the primary risk factors for pneumonia. Both very young children and older adults are at higher risk for pneumonia. Infants and toddlers have immature immune systems and narrower airways, making them more susceptible to respiratory infections that can progress to pneumonia. Adults over 65 are also at higher risk due to weakened immune systems and a decline in lung function.

People with weakened immune systems are more susceptible to infections in general, including pneumonia. This can be due to various conditions or medications that suppress the immune system, such as HIV/AIDS, organ transplantation, chemotherapy, or long-term steroid use.

Underlying chronic lung conditions like COPD (chronic obstructive pulmonary disease) or asthma can damage the lungs and make them more vulnerable to infection. People with these conditions already have difficulty clearing mucus from their airways, which can allow bacteria or viruses to build up and lead to pneumonia.

Smoking irritates and damages the lungs, making them more susceptible to infection. It also impairs the body’s ability to clear mucus from the airways, which can increase the risk of pneumonia. Having a cold or the flu can irritate and weaken the lungs, making them more prone to secondary bacterial pneumonia.

Additional Risk Factors:

People who are in the hospital, especially those on ventilators, are at higher risk of pneumonia due to exposure to healthcare settings and potential ventilator-associated pneumonia. Not getting enough essential nutrients can weaken the immune system and increase the risk of pneumonia, particularly in young children and older adults.

Heavy alcohol consumption can weaken the immune system and impair the body’s ability to fight infection.

While not directly causing pneumonia, poor dental hygiene can increase the risk of bacteria entering the lungs through aspiration (inhalation). This is especially concerning for those with dentures.

Types of Pneumonia

Pneumonia can be caused by a variety of invaders, and these different culprits lead to distinct types of pneumonia. Here’s a breakdown of the main categories:

1. Bacterial Pneumonia: This is the most common type, especially in young children and older adults. Here’s a closer look:
   • Cause: The culprit is usually the bacterium Streptococcus pneumoniae, but other bacteria can also be involved.
   • Transmission: Spreads through inhalation of respiratory droplets from an infected person coughing or sneezing.
   • Symptoms: Often comes on abruptly with a high fever, chills, cough with green or yellow mucus, chest pain that worsens with breathing, shortness of breath, fatigue, and rapid breathing.
   • Treatment: Typically treated with antibiotics, and most people recover fully with prompt treatment.
   • Differentiation: Compared to other types, bacterial pneumonia often has a more sudden onset and can be quite severe.
2. Viral Pneumonia: This type accounts for roughly a third of pneumonia cases and can affect people of all ages.
   • Cause: Caused by various viruses, including influenza (flu), respiratory syncytial virus (RSV), and rhinovirus (common cold).
   • Transmission: Similar to bacterial pneumonia, it spreads through inhalation of respiratory droplets from an infected person.
   • Symptoms: Often starts with milder upper respiratory symptoms like runny nose, sore throat, and progresses to cough, fever, chills, fatigue, and shortness of breath. Symptoms tend to be less severe than bacterial pneumonia.
   • Treatment: Usually involves supportive care like rest, fluids, pain relievers, and medications to manage cough. Antibiotics are not effective against viruses. In severe cases, hospitalization might be needed.
   • Differentiation: Viral pneumonia often has a more gradual onset compared to bacterial pneumonia, and symptoms are generally milder.
3. Mycoplasma Pneumonia: This is a less common type caused by a specific type of bacteria-like organism called Mycoplasma pneumoniae.
   • Cause: Mycoplasma pneumoniae is the culprit behind this type.
   • Transmission: Similar to bacterial and viral pneumonia, it spreads through inhalation of respiratory droplets.
   • Symptoms: Often referred to as “walking pneumonia” because symptoms can be mild and allow people to remain somewhat functional. Symptoms include cough, fatigue, headache, sore throat, and low-grade fever.
   • Treatment: May be treated with antibiotics specifically effective against Mycoplasma. In some cases, no antibiotics are needed if symptoms are mild.
   • Differentiation: Mycoplasma pneumonia typically has milder symptoms compared to bacterial pneumonia and a more gradual onset compared to both bacterial and viral types.
4. Fungal Pneumonia: This is the least common type and primarily affects people with weakened immune systems.
   • Cause: Caused by inhaling fungal spores from the environment.
   • Transmission: Differs from other types as it doesn’t spread from person to person.
   • Symptoms: Symptoms can vary depending on the type of fungus but often include cough, fever, shortness of breath, and weight loss.
   • Treatment: Antifungal medications are used for treatment, and the specific medication depends on the type of fungus identified.
   • Differentiation: Fungal pneumonia is less common and often occurs in immunocompromised individuals. It can be difficult to diagnose and may require specialized testing.
5. Aspiration Pneumonia: This type arises when foreign material, such as food, liquids, or vomit, is inhaled into the lungs.
   • Cause: Inhaling foreign material into the lungs.
   • Transmission: Not contagious.
   • Symptoms: Symptoms can vary depending on the material inhaled but often include cough, fever, shortness of breath, and wheezing.
   • Treatment: Treatment depends on the severity and may involve antibiotics, medications to thin mucus, and supportive care like oxygen therapy.
   • Differentiation: Aspiration pneumonia is not caused by an infectious agent but by the inhalation of foreign material.

The main differences between these types of pneumonia lie in the cause, transmission, typical symptoms, and treatment approaches. Bacterial and viral pneumonia are most common and spread through respiratory droplets. Bacterial pneumonia often has a more abrupt and severe presentation, while viral pneumonia is generally milder. Mycoplasma pneumonia often has a gradual onset and milder symptoms compared to bacterial pneumonia. Fungal pneumonia is uncommon and typically affects immunocompromised individuals. Aspiration pneumonia is not contagious and arises from inhaling foreign material.

How is Pneumonia Transmitted?

Inhalation is the most common mode of transmission for pneumonia caused by bacteria and viruses. When an infected person coughs, sneezes, talks, or even sings, they expel tiny droplets containing the bacteria or virus that causes pneumonia. These droplets can travel short distances through the air and be inhaled by another person.

While less common than inhalation, pneumonia can also spread through contact with contaminated surfaces. If an infected person coughs or sneezes into their hands and then touches a surface like a doorknob, table, or light switch, the virus or bacteria can live on that surface for a short time. If another person touches the contaminated surface and then touches their face (eyes, nose, mouth), they can become infected.

In some rare instances, pneumonia can arise from inhaling foreign material, including fluids or stomach contents. Aspiration Pneumonia can occur in people with swallowing difficulties due to conditions like stroke or neurological disorders. It can also happen in infants with reflux or during vomiting episodes.

In even rarer cases, pneumonia can spread through the bloodstream. Bloodstream Infection is most common in healthcare settings and usually occurs when bacteria from another part of the body, like the skin or urinary tract, enters the bloodstream and travels to the lungs.

Here’s a breakdown of how this applies to different types of pneumonia:

• Bacterial and Viral Pneumonia: Spread primarily through inhalation of respiratory droplets.
• Mycoplasma Pneumonia: Spreads similarly to bacterial and viral pneumonia through inhalation of respiratory droplets.
• Fungal Pneumonia: Not contagious and does not spread from person to person. People inhale fungal spores from the environment.
• Aspiration Pneumonia: Not contagious. Caused by inhaling foreign material.

What are some of the Preventative Measures Used to Avoid Contracting Pneumonia?

Frequent hand washing is crucial to prevent the spread of pneumonia-causing germs. Practice good cough etiquette by coughing or sneezing into a tissue or your elbow. Maintain a clean environment by disinfecting frequently touched surfaces. Get vaccinated against influenza and pneumococcus (depending on age and risk factors)..

 Vaccinations:

Pneumococcal Vaccination protects against specific strains of Streptococcus pneumoniae, a major cause of bacterial pneumonia. The Centers for Disease Control and Prevention (CDC) recommends pneumococcal vaccination for all adults 65 years and older, and younger adults with certain chronic health conditions like heart disease, diabetes, or chronic lung disease. There are also pneumococcal vaccines recommended for children at specific ages.

Getting an annual influenza (flu) vaccine is essential in preventing influenza and its potential complications, including pneumonia. The flu virus can weaken the lungs and make them more susceptible to secondary bacterial pneumonia.

Good Hygiene Practices:

Frequent Handwashing is one of the simplest and most effective ways to prevent the spread of germs that cause pneumonia. Wash your hands thoroughly with soap and water for at least 20 seconds, especially after coughing, sneezing, blowing your nose, using the toilet, and before eating or preparing food.

Practice good cough etiquette and respiratory hygiene by coughing or sneezing into a tissue or your elbow. This helps prevent the spread of respiratory droplets containing germs. Dispose of used tissues properly and wash your hands after coughing or sneezing.

If someone you know is sick with a respiratory infection, try to avoid close contact with them. This may mean maintaining a physical distance, not sharing personal items, and avoiding touching your face (eyes, nose, mouth) after being around someone who is sick.

Complications of Pneumonia

Pneumonia can often be effectively treated, but in some cases, it can lead to serious complications. These complications are especially concerning for vulnerable populations, such as young children, older adults, and people with weakened immune systems. Here’s a look at some potential complications of pneumonia:

Respiratory Failure is a life-threatening condition where the lungs are unable to take in enough oxygen or remove enough carbon dioxide from the bloodstream. Symptoms of respiratory failure include severe shortness of breath, rapid breathing, bluish skin or nail beds (cyanosis), confusion, and disorientation. People with respiratory failure may require mechanical ventilation (a breathing machine) to assist with breathing.

Sepsis is a life-threatening condition that occurs when the body’s response to infection injures its own tissues and organs. Bacteria from the lungs can enter the bloodstream and spread throughout the body, triggering a widespread inflammatory response. Symptoms of sepsis can include fever, chills, rapid heart rate, rapid breathing, confusion, and severe pain or discomfort. Sepsis is a medical emergency and requires prompt treatment with antibiotics and supportive care.

A lung abscess is a collection of pus that forms within the lung tissue. It can develop if a pocket of infection is not effectively cleared by the body’s immune system or antibiotic treatment. Symptoms of a lung abscess can include cough that produces foul-smelling mucus, fever, chills, chest pain, and night sweats. Treatment for a lung abscess typically involves antibiotics and may require drainage of the pus with a needle or surgery.

Pleural Effusion (Fluid Buildup Around the Lungs) is a collection of fluid in the space between the two layers of pleura, the thin membranes that line the lungs and chest cavity. This fluid buildup can interfere with lung expansion and make breathing difficult. Symptoms of pleural effusion can include chest pain that worsens with breathing or coughing, shortness of breath, and cough. Treatment for pleural effusion depends on the underlying cause and may involve removing the fluid with a needle (thoracentesis) or surgery.

Additional Complications:

• Acute Respiratory Distress Syndrome (ARDS): This is a severe form of respiratory failure that can occur as a complication of pneumonia. ARDS can cause significant damage to the lungs and require intensive care support, including mechanical ventilation.
• Kidney Failure: Severe pneumonia and sepsis can put stress on the kidneys and lead to kidney failure, especially in vulnerable populations.
• Heart Failure: Pneumonia can also place strain on the heart, and in some cases, can worsen existing heart failure.

How is Pneumonia Diagnosed?

Diagnosing pneumonia often involves a combination of a doctor’s evaluation, your medical history, and various tests. 

Your doctor will listen to your lungs with a stethoscope to check for abnormal sounds like crackling or wheezing, which can indicate pneumonia. They will also take your temperature, blood pressure, oxygen level, and heart rate.

Your doctor will ask you about your symptoms, when they started, and any other medical conditions you have. They will also inquire about potential risk factors such as smoking or recent respiratory infections.

Diagnostic Tests:

• Chest X-Ray: This is a common imaging test used to visualize your lungs and identify signs of pneumonia, such as areas of inflammation or fluid buildup.
  
• Sputum Test: You may be asked to cough up a sample of mucus (sputum) to analyze for the presence of bacteria or other pathogens. This test can help identify the specific cause of pneumonia and determine the most appropriate antibiotic treatment. Not everyone can produce sputum, and in some cases, this test may not be necessary.
  
• Pulse Oximetry: This simple test uses a clip placed on your finger to measure the amount of oxygen in your blood. Low oxygen levels may indicate pneumonia is affecting your lungs’ ability to absorb oxygen.
  
• Blood Tests: While not diagnostic for pneumonia itself, blood tests can help assess the severity of the infection by checking for signs of inflammation, such as elevated white blood cell count. Blood cultures may also be done to rule out sepsis, a serious complication of pneumonia.
  
• Other Tests: In some cases, depending on the severity of your condition or if there’s difficulty reaching a diagnosis, additional tests like a CT scan of the chest or a bronchoscopy (examining the airways with a thin tube) might be needed.

How is Pneumonia Treated?

Pneumonia treatment depends on the type and severity of the infection, along with your overall health. 

Bacterial Pneumonia is the most common type and is treated with antibiotics. The specific antibiotic used depends on the identified bacteria and its susceptibility. Antibiotics are ineffective against viral or fungal pneumonia. However, specific antibiotics may be used for Mycoplasma pneumonia in some cases.

Supportive Care:

This is essential for all types of pneumonia and focuses on symptom relief and recovery:

• Rest: Your body needs energy to fight the infection.
• Fluids: Staying hydrated loosens mucus and prevents dehydration, which can worsen symptoms.
• Pain relievers: Medications like ibuprofen or acetaminophen can manage fever, headache, and muscle aches.
• Cough suppressants (use with caution): These may help with a dry, hacking cough that disrupts sleep or breathing, but not a productive cough with mucus.
• Oxygen therapy: If your blood oxygen levels are low, you may need supplemental oxygen.

Hospitalization:

Some cases require hospitalization, especially if you have severe symptoms such as difficulty breathing, and/or confusion. Hospitalization may also be considered if you have a weakened immune system or suffer from underlying chronic health conditions. You may also be hospitalized if you are an older adult or young child due to greater susceptibility to the disease, or if oxygen therapy or more intensive treatments are required.

Additional Therapies:

• Antiviral medications: For viral pneumonia, these can help reduce symptom duration and severity.
• Antifungal medications: These are the mainstay of treatment for fungal pneumonia.

Length of Treatment:

The duration varies depending on the type of pneumonia, your response, and overall health. A typical course of antibiotics for bacterial pneumonia might last 7-10 days. Always complete the entire course, even if you feel better, to ensure the infection is eradicated.

Recovery:

Most people recover fully with prompt diagnosis and treatment. However, recovery, especially for older adults or those with chronic conditions, can take several weeks.

What medications are most often prescribed for Pneumonia?

Macrolides: These are often the first-line antibiotics for treating pneumonia due to their broad spectrum of activity against many bacteria that cause it. Examples include:

• Azithromycin (Zithromax)
• Clarithromycin (Biaxin)
• Erythromycin

Beta-lactam antibiotics: These are another common class of antibiotics used for pneumonia, particularly in hospital settings. They may be used alone or combined with other antibiotics. Examples include:

• Amoxicillin (Amoxil)
• Amoxicillin-clavulanate (Augmentin)
• Ampicillin
• Cefuroxime (Ceftin)
• Ceftriaxone (Rocephin)

Fluoroquinolones: These antibiotics are sometimes prescribed for pneumonia, but their use is becoming more restricted due to concerns about antibiotic resistance. Examples include:

• Levofloxacin (Levaquin)
• Ciprofloxacin (Cipro)