Pneumonia is an infection in one or both lungs. The infection may be caused by fungi, bacteria, or viruses. Pneumonia causes inflammation in your lung’s air sacs, also referred to as alveoli. The alveoli fill with fluid or pus, making it difficult to breathe. Symptoms of pneumonia can range from mild to life threatening. In fact, pneumonia causes more deaths worldwide than any other illness. The severity of pneumonia usually depends on the cause of the inflammation or by the type of organism causing the infection, a person’s age, and their general health.
There are five major types of pneumonia. They are:
Bacterial pneumonia can affect anyone at any age. It can develop on its own or after a serious cold or flu. The most common cause of bacterial pneumonia is streptococcus pneumoniae. Bacterial pneumonia can also be caused by Chlamydophila pneumonia or legionella pneumophila. Pneumocystis jiroveci pneumonia is sometimes seen in those who have weak immune systems, due to illnesses like AIDS or cancer.
In most cases, respiratory viruses can cause pneumonia, especially in young children and the elderly. Pneumonia is usually not serious and lasts a short time. However, the flu virus can cause viral pneumonia to be severe or fatal. It’s especially harmful to pregnant women or individuals with heart or lung issues. Invading bacteria can cause complications with viral pneumonia.
Mycoplasmas are not viruses or bacteria, but they have traits common to both. They are the smallest agents of disease that affect humans. Mycoplasmas generally cause mild cases of pneumonia, most often in older children and young adults.
Other Types of Pneumonia
Many additional types of pneumonia affect immune-compromised individuals. Tuberculosis and pneumocystis carinii pneumonia (PCP) generally affect persons with AIDS. In fact, PCP can be one of the first signs of illness in people with AIDS.
Less common types of pneumonia can also be serious. Pneumonia can be caused by inhaling food, dust, liquid, gas, and by various fungi.
No one is immune to pneumonia, but there are certain factors that can raise your risks:
- previous stroke or problems swallowing: People who have had a stroke, have problems swallowing, or are bedridden can easily develop pneumonia.
- age: Infants from birth to age two are at risk for pneumonia, as are individuals age 65 or older.
- weakened immune system: This includes people who take medications (steroid drugs and anti-cancer drugs) that weaken the immune system and people with HIV, AIDS, or cancer.
- drug abuse: This includes excessive alcohol consumption and smoking.
- certain medical conditions: Asthma, cystic fibrosis, diabetes, and heart failure raise your risks for pneumonia.
The general symptoms of bacterial pneumonia can develop quickly and may include:
- chest pain
- shaking chills
- dry cough
- muscle aches
- rapid breathing
- rapid heartbeat
- difficulty breathing
Some symptoms may indicate a medical emergency. These symptoms include:
- skin with bluish tone (from lack of oxygen)
- blood in sputum (coughed-up mucus)
- labored breathing
- high fever (103 °F or higher)
- rapid heartbeat
Pneumonia can be easily overlooked as the cause of an illness because it often resembles a cold or the flu. However, it usually lasts longer and symptoms seem more severe than these other conditions.
Detailed Patient History
To determine whether or not a patient has pneumonia, doctors generally inquire about a patient’s signs and symptoms. Questions they may include:
- What are your symptoms and when did they begin?
- What were your recent travels and activities?
- What was your recent exposure to animals?
- What was your recent exposure to individuals who are sick?
- What are your past and current medical issues?
- What medications are you currently taking?
- What is your smoking history?
- Have you recently had any vaccinations or illnesses?
Crackling and bubbling sounds in the chest during inhalation are usually indicators of pneumonia. Wheezing may also be present. Additionally, your doctor may have trouble hearing normal breathing sounds in different areas of the chest.
Chest X-rays can be used to determine if infection is present in your lungs. However, chest X-rays won’t show your type of pneumonia. Blood tests can provide a better picture of the type of pneumonia. Also, blood tests are necessary to see if the infection is in your bloodstream.
Additional tests that may be required include:
- Chest computed tomography (CT scan): A CT scan is similar to an X-ray, but the pictures provided by this method are highly detailed. This painless test provides a clear and precise picture of the chest and lungs.
- Sputum test: This test will examine the sputum (the mucus you cough up) to determine what type of pneumonia is present.
- Pleural fluid test: If there is fluid apparent in the pleural space (the space between the tissue that covers the outside of your lungs and the inside of your chest cavity), a fluid sample can be taken to help determine if the pneumonia is bacterial or viral.
- Pulse oximetry: This test measures the level of oxygen blood saturation by attaching a small sensor to your finger. Pneumonia can prevent normal oxygenation of blood.
- Bronchoscopy: When antibiotics fail, this method is used to view the airways inside the lungs to determine if blocked airways are contributing to the pneumonia.
The type of treatment prescribed for pneumonia primarily depends on what type of pneumonia is present and its severity. In many cases, pneumonia can be treated at home.
The typical treatment plan for pneumonia includes taking all prescribed medications and participating in follow-up care. A chest x-ray may be ordered to ensure your pneumonia has been successfully treated.
Treating Bacterial Pneumonia
Antibiotics are used to treat this type of pneumonia. Antibiotics should be taken as directed. If antibiotics are ceased before treatment is complete, the pneumonia may return. Most people will improve after one to three days of treatment.
Treating Viral Pneumonia
Antibiotics are useless if a virus is the cause of pneumonia. However, antiviral drugs can help treat the condition. Symptoms usually improve within one to three weeks.
Anyone with diabetes, asthma, and other severe or chronic health problems, is at risk for pneumonia. However, in many cases, it can be prevented with vaccines against bacterial pneumonia and flu. Quitting smoking will definitely lower the risk of pneumonia.
Written by: Bree Normandin
Published on Aug 07, 2012
Medically reviewed by Brenda B. Spriggs, MD, MPH, FACP