Pneumonia: Symptoms, Causes, Treatment, and Prevention

What is Pneumonia?

Pneumonia is a lung infection that can range from mild to severe, sometimes even requiring hospitalization. The National Heart, Lung, and Blood Institute states that some individuals recover and can resume their normal activities within 1 to 2 weeks, while for others, recovery may take a month or more. 

Pneumonia is caused by various microorganisms, including bacteria, viruses, and fungi. When these germs invade the lungs, they can overcome the body's immune defenses, leading to an infection. The infection causes the air sacs in one or both lungs to become inflamed. This inflammation can cause the air sacs to fill with fluid or pus.

Pneumonia can affect anyone, but it can be particularly serious for infants, young children, people over the age of 65, and those with weakened immune systems or underlying health conditions. These groups are more susceptible to severe complications and may require prompt medical attention to manage the infection effectively.

Types of Pneumonia

Pneumonia can be classified based on the type of germs that cause the infection and the setting in which the infection is acquired:

Bacterial Pneumonia

Bacterial pneumonia is the most common type of pneumonia. It is typically more severe than other forms and can develop rapidly. This type of pneumonia often follows a cold or the flu and can affect one part of the lung (lobar pneumonia) or be distributed throughout the lung (bronchopneumonia).

Bacterial pneumonia is commonly caused by several types of bacteria, with Streptococcus pneumoniae being the most frequent. Other bacteria that can cause pneumonia include:

• Mycoplasma pneumoniae: Often leads to walking pneumonia.
• Haemophilus influenzae: Another common cause, especially in adults.
• Legionella pneumophila: Causes Legionnaires' disease, a severe form of pneumonia.

Viral Pneumonia

Viral pneumonia often presents symptoms similar to those of the flu. It tends to be less severe than bacterial pneumonia but can still lead to significant health issues, especially in vulnerable groups such as children, older adults, and those with weakened immune systems.

Viral pneumonia is caused by various viruses, which can include:

• Influenza Virus: A common cause during flu season.
• Respiratory Syncytial Virus (RSV): Particularly affects young children.
• SARS-CoV-2: The virus responsible for COVID-19.
• Adenovirus: Can cause respiratory infections leading to pneumonia.

Fungal Pneumonia

Fungal pneumonia is less common and typically affects people with weakened immune systems. The fungi responsible for this type of pneumonia can be found in soil and bird droppings.

Fungi responsible for pneumonia include:

• Cryptococcus: Found in bird droppings.
• Histoplasmosis: Common in certain geographic areas, particularly in soil.
• Coccidioidomycosis: Known as valley fever, found in the southwestern United States.

Aspiration Pneumonia

Aspiration pneumonia occurs when you inhale food, drink, vomit, or saliva into your lungs. This can happen if something disturbs your normal gag reflex, such as a brain injury, excessive alcohol use, or a swallowing problem.

Walking Pneumonia

Walking pneumonia refers to the mild nature of the illness, allowing individuals to remain active. It is called "walking pneumonia" because those affected may not feel sick enough to stay in bed and continue their daily activities.

Symptoms of Pneumonia

Recognizing the symptoms of pneumonia early is crucial for prompt treatment and better outcomes. Symptoms can vary widely based on the type of pneumonia and the age and health of the affected individual.

Main Symptoms

• Chest pain, especially when breathing deeply or coughing
• Persistent cough that produces phlegm or mucus (yellow, green, or bloody)
• Fatigue and general tiredness
• Fever, chills, and sweating
• Shortness of breath and rapid breathing
• Muscle pain and body aches
• Nausea, vomiting, and sometimes diarrhea
• Headache
• Bluish tint to lips or fingernails (indicating low oxygen levels)
• Confusion or delirium

Symptoms in Specific Groups

Pneumonia in infants and young children can present differently than in adults. According to the World Health Organization (WHO), pneumonia was responsible for 14% of all deaths in children under the age of 5, claiming the lives of more than 740,000 children in 2019. They may not show clear symptoms but can exhibit signs such as:

• Fever: Often higher than in adults, typically reaching temperatures of 100.4°F (38°C) or higher.
• Rapid Breathing: Faster breathing than normal.
• Cough: Persistent and sometimes severe, which can be dry or produce mucus. It might interfere with sleep and daily activities.
• Restlessness: Increased irritability or fussiness, which can make it difficult to console the child. They may cry more than usual and seem generally uncomfortable.
• Feeding Problems: Difficulty eating or lack of appetite, which can result in reduced intake of breast milk or formula. Infants may struggle to suck or swallow and show less interest in feeding.
• Vomiting: Frequent vomiting can also be a sign of pneumonia, especially when associated with coughing or feeding difficulties. It can lead to dehydration and requires careful monitoring.

Older adults might experience more subtle symptoms of pneumonia. As people age, their immune systems naturally weaken, making it harder to fend off infections like pneumonia. Older adults are also more likely to have chronic health conditions that can increase the risk of pneumonia. They often have:

• Lower than Normal Body Temperature: Especially in those over 65, body temperature may fall below the normal range (98.6°F or 37°C). Instead of a high fever, older adults may present with a mild fever or even hypothermia, which is a body temperature below 95°F (35°C). This atypical presentation can delay diagnosis and treatment.
• Confusion or Delirium: Sudden changes in mental state or increased confusion.
• Fatigue: More pronounced than in younger adults, older individuals may feel an overwhelming sense of tiredness and weakness. 
• Worsening of Pre-existing Conditions: Such as heart failure or chronic obstructive pulmonary disease (COPD).

People with weakened immune systems, including those undergoing chemotherapy, living with HIV/AIDS, or taking immunosuppressive drugs, may have atypical symptoms:

• Milder Fever: Or even no fever at all.
• Less Noticeable Symptoms: Such as a slight cough or mild shortness of breath.
• Increased Risk of Severe Complications: Rapid progression to severe pneumonia if not treated promptly.

Recognizing these symptoms and seeking medical attention is important. For those unsure about their symptoms, the Symptom Checker can be a useful tool, but remember to consult a healthcare professional for an accurate diagnosis.

Diagnosis of Pneumonia

Accurate diagnosis of pneumonia is crucial for effective treatment. Healthcare providers use a combination of medical history, physical exams, and diagnostic tests to identify pneumonia and its cause:

Physical Exam and Medical History

The first step in diagnosing pneumonia involves a thorough physical exam and a review of the patient's medical history. 

During the physical exam, the doctor listens to the patient's lungs with a stethoscope to detect abnormal sounds such as crackling, bubbling, or rumbling, which can indicate fluid or inflammation. The doctor will also ask about symptoms, recent illnesses, travel history, and exposure to sick individuals.

Imaging Tests

Imaging tests are essential tools for diagnosing pneumonia. They help visualize the lungs and identify areas of infection or inflammation.

• Chest X-Rays: The most common imaging test for pneumonia. X-rays can reveal the presence of infection, the extent of lung involvement, and any complications such as pleural effusion.
• CT Scans: Sometimes used for more detailed images if the chest X-ray results are inconclusive or if complications are suspected. CT scans provide a clearer and more comprehensive view of the lungs.

Laboratory Tests

Laboratory tests help identify the specific cause of pneumonia, which is crucial for determining the appropriate treatment.

• Blood Tests: These tests can detect the presence of infection in the body and help identify the type of microorganism causing the pneumonia.
• Sputum Tests: The patient is asked to cough up a sample of sputum (mucus from the lungs), which is then analyzed in a lab to determine the cause of the infection.
• Pulse Oximetry: A non-invasive test that measures the oxygen levels in the blood to determine how well the lungs are functioning.
• Arterial Blood Gas Test: In some cases, this test may be performed to measure the levels of oxygen and carbon dioxide in the blood.

Treatment Options for Pneumonia

Treatment for pneumonia depends on the type and severity of the infection, as well as the patient's overall health. There are both medical treatments and at-home care options available.

Medical Treatments

Bacterial pneumonia is typically treated with antibiotics. The specific type of antibiotic prescribed depends on the bacterium causing the infection. It's essential to complete the full course of antibiotics even if symptoms improve, to ensure the infection is fully eradicated.

Antiviral medications can be used to treat viral pneumonia caused by specific viruses, such as influenza or COVID-19. These medications help reduce the severity and duration of symptoms but are not effective against bacterial infections.

Fungal pneumonia requires antifungal medications. The choice of medication depends on the type of fungus causing the infection and the patient's overall health. Treatment duration can vary and may be longer than for bacterial or viral pneumonia.

Hospital Care for Severe Cases

Severe cases of pneumonia may require hospitalization. Hospital treatments can include:

• IV Fluids: To maintain hydration and support recovery.
• Oxygen Therapy: To ensure adequate oxygen levels in the blood.
• Breathing Treatments: Such as nebulizers or inhalers to help open airways and improve breathing.

At-Home Care

For mild cases of pneumonia, at-home care can be effective:

• Rest and Hydration: Ensuring plenty of rest and drinking fluids to stay hydrated.
• Over-the-Counter Medications: To relieve symptoms such as fever, pain, and cough (always consult with a healthcare provider before using cough suppressants).
• Following Prescribed Treatments: Adhering to the full course of any prescribed medications and following any additional advice from healthcare providers.

Complications of Pneumonia

Even with treatment, pneumonia can lead to serious complications, particularly in high-risk individuals.

• Bacteremia: Bacteremia occurs when bacteria from the lungs enter the bloodstream, potentially spreading the infection to other organs and causing sepsis, a life-threatening condition.
• Respiratory Failure: Severe pneumonia can lead to respiratory failure, where the lungs are unable to provide enough oxygen to the body or remove carbon dioxide. This may require mechanical ventilation to support breathing.
• Pleural Effusion: Pneumonia can cause fluid to accumulate in the pleural space (the area between the lungs and the chest wall). If the fluid becomes infected, it may need to be drained through a chest tube or surgery.
• Lung Abscess: A lung abscess occurs when a pocket of pus forms in the lung. Treatment typically involves antibiotics, but drainage or surgery may be necessary in severe cases.
• Acute Respiratory Distress Syndrome (ARDS): ARDS is a severe form of respiratory failure that can occur in people with severe pneumonia. It involves widespread inflammation in the lungs and requires intensive care, including mechanical ventilation.

Prevention of Pneumonia

Preventing pneumonia involves a combination of vaccination, healthy lifestyle practices, and specific measures for at-risk groups.

Vaccination

Several vaccines can help protect against pneumonia and related illnesses:

• Pneumococcal Vaccines: Protect against pneumococcal bacteria, a common cause of bacterial pneumonia. According to the CDC, pneumococcal vaccines are the most effective method for preventing serious pneumococcal infections.
• Influenza Vaccines: Help prevent flu, which can lead to pneumonia.
• COVID-19 Vaccines: Reduce the risk of severe illness and pneumonia caused by the SARS-CoV-2 virus.
• Other Relevant Vaccines: Vaccines for diseases like Hib, measles, and whooping cough can also help prevent pneumonia.

Healthy Lifestyle Practices

Adopting healthy habits can strengthen the immune system and reduce the risk of pneumonia:

• Hand Hygiene: Regularly washing hands with soap and water or using hand sanitizer.
• Smoking Cessation: Avoiding smoking and exposure to secondhand smoke.
• Maintaining a Healthy Immune System: Eating a balanced diet, exercising regularly, and getting adequate sleep.