Different causes of pneumonia can also lead to varying symptoms.
Bacterial Pneumonia
Bacteria are a common cause of pneumonia in adults. They can cause a series of classic symptoms, including:
Other bacterial pneumonia symptoms include:
- High fever
- Chills
- Rapid breathing
- Pain when coughing or breathing deeply
- Shortness of breath
- Exhaustion
- Loss of appetite
Bacterial pneumonias tend to be very severe and cause more noticeable symptoms than other types of pneumonia, with a higher likelihood of needing hospital treatment.
Types of bacteria that cause pneumonia include:
- Streptococcus pneumoniae, the most common cause in the United States
- Legionella pneumophila, the cause of Legionnaires’ disease, or legionellosis
- Mycoplasma pneumoniae, which usually infects younger adults who work in crowded areas, such as schools, homeless shelters, or prisons
- Chlamydophila pneumoniae, which causes a mild pneumonia infection that usually affects people older than 60 years
- Haemophilus influenzae type B (Hib)
Hospital-Acquired Pneumonia
This form of pneumonia is acquired during or after a hospital stay, and it can be severe and even fatal. It’s often more difficult for people to fight off this infection because they’re already sick, and the germs and bacteria in the hospital environment may be more resistant to treatment than those out in the community.
The first sign of hospital-acquired pneumonia may be confusion or cognitive changes in older adults. Other symptoms include:
- Fever or chills
- A cough with greenish phlegm
- Loss of appetite
- Nausea and vomiting
- Chest pain
- Shortness of breath
- Decreased blood pressure.
- A drop in oxygen levels in the blood
You may have a higher risk of hospital-acquired pneumonia if the following apply to you:
- You’re an older adult.
- You’ve had chest surgery or other major surgery.
- You have chronic lung disease.
- You are immunocompromised.
- You have alcohol use disorder.
- You experience swallowing problems and breathe saliva or food into your lungs, which can happen after a stroke.
- You’re on a ventilator.
- You’re experiencing cognitive side effects and reduced mental alertness due to medication or illness.
Walking Pneumonia
A mild case of bacterial or viral pneumonia, often called walking pneumonia, features symptoms similar to the common cold, including:
- Persistent dry cough that often gets worse at night
- Low-grade fever
- Shortness of breath
- Fatigue or tiredness
- Chest pain that gets worse when you take a deep breath or cough
- Loss of appetite
- Sore throat
Viral Pneumonia
Viruses account for approximately one-third of all pneumonias. Viral pneumonias tend to clear up in about one to three weeks, but they can increase your risk of bacterial pneumonia. They’re usually less severe than bacterial pneumonias, but some viruses like influenza and SARS-CoV-2 can be very severe.
However, within a couple of days, these symptoms typically worsen.
Adults with viral pneumonia can also expect to develop:
- Worsening cough
- Increasing breathlessness
- More severe muscle pain
- Sometimes, high fever and a blue tint to the lips
The influenza virus is a common cause of viral pneumonia, which tends to be more severe in individuals with heart or lung disease, adults ages 65 and older, and young children. Individuals with compromised immune systems also have a higher risk of influenza progressing to pneumonia.
Not only can influenza cause pneumonia — it can also predispose people to bacterial pneumonia. This is a good reason to get the yearly flu shot.
SARS-CoV-2, the virus that causes COVID-19, can also cause viral pneumonia. COVID pneumonia often affects both lungs and tends to spread slowly, lasting longer and causing more damage than other types of pneumonia. If you develop COVID pneumonia, you’ll likely need admission to the hospital.
Fungal Pneumonia
The symptoms of fungal pneumonia are often similar to those of other forms of pneumonia, including fever, dry cough, shortness of breath, and fatigue. However, the symptoms and their severity may depend on the type of fungus. Four types of fungi that live in soil are known causes of pneumonia:
- Coccidioides immitis and Coccidioides posadasii are two related fungi common to the southwestern United States. Both can cause coccidioidomycosis, also known as cocci or valley fever.
- Histoplasma capsulatum is found in the central and eastern United States, especially areas around the Ohio and Mississippi River valleys, and it causes a disease called histoplasmosis.
- Cryptococcus is a fungi present in soil and bird droppings all across the country.
- Blastomyces, which can cause blastomycosis, is found largely in the midwestern, south-central, and southeastern United States.
Most people who inhale these fungi don’t get sick, but if your immune system doesn’t function well, you may develop pneumonia.
In hospitalized patients with compromised immune systems, opportunistic fungal pneumonia can occur and may involve multiple fungi, including candida and aspergillus.
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