Lung Disease & Respiratory Health Center

Font Size

Viral Pneumonia

Viral Pneumonia Overview

Pneumonia is an infection or inflammation of the lungs. It can be in just one part of the lungs, or it can involve many parts. Pneumonia is caused by bacteria, viruses, fungi, and other microorganisms. The severity of pneumonia depends on which organism is causing the infection. Viral pneumonias are usually not very serious, but they can be life-threatening in very old and very young patients, and in people whose immune systems are weak.

Even severe acute respiratory syndrome (SARS), which is believed to have a viral cause, has caused very few deaths (approximately 3-4% of all cases) as of March 19, 2003. For the latest information on this illness, visit the Centers for Disease Control and Prevention Web site.

Viral Pneumonia Causes

Viral pneumonia can be caused by influenza virus, respiratory syncytial viru s (RSV), and the herpes or varicella viruses, including those that cause the common cold (parainfluenza and adenoviruses).

Influenza A and B usually occur in the winter and spring. In addition to the respiratory symptoms, you can get headache, fever, and muscle aches. Your chance of catching the flu falls a lot (but is not totally prevented) if you get a " flu shot" every year.

Respiratory syncytial virus (RSV) is most common in the spring. It usually infects children and can cause outbreaks in daycare centers.

Herpes or varicella pneumonia are rare unless you are infected with chickenpox.

Adenovirus and parainfluenza viral pneumonias are often accompanied by cold symptoms such as runny nose and pinkeye ( conjunctivitis).

Although the specific pathogen responsible for SARS has not been identified as of March 19, 2003, a viral etiology is believed to be responsible.

Viral Pneumonia Symptoms

Low-grade fever (less than 102° F)

Coughing up small amounts of mucus

Tiredness

Muscle aches

Symptoms of pneumonia caused by a virus usually go on for several days to a few weeks before you call your doctor. Most people with bacterial pneumonia get sick very quickly and see a doctor within a few days.

When to Seek Medical Care

Go to your hospital's emergency department or call your doctor if you develop any of these symptoms:

Shortness of breath, either at rest or with just a little exertion

Severe chest pain

Severe weakness

Coughing up blood

Vomiting so much that you are dehydrated

Exams and Tests

Your doctor will check your temperature, heart rate, and blood pressure. A small clamp, which looks like a clothespin, can be put on your finger to check your blood oxygen level. Your doctor will listen to your heart and lungs to help determine the cause of your symptoms and the severity of your illness. If it is possible that you have pneumonia, you will probably have an x-ray of your chest. Blood tests are not very helpful in diagnosing pneumonia except in special circumstances.

Influenza A and B are usually diagnosed clinically, which means the symptoms give the diagnosis-fever, headache, body aches, tiredness, cough, runny nose. No lab tests are needed. Sometimes, secretions from your nose can be tested to help identify the organism.

Varicella pneumonia is usually diagnosed clinically because it usually happens during an outbreak of the chickenpox.

If your doctor suspects respiratory syncytial virus (RSV), a swab of your nose secretions can be sent for testing by a laboratory. Children and infants are more likely to be tested for RSV, because this virus can be more serious in them.

Adenovirus and parainfluenza virus are not likely to cause life-threatening illness. Tests are rarely done if these viruses are suspected to be the cause of pneumonia.

1 | 2 | 3

Next Page >

WebMD Medical Reference from eMedicineHealth