Doctor's Notes on Viral Pneumonia
Viral pneumonia is an infection of the lung by a viral type or strain. Signs and symptoms of viral pneumonia common to most viral lung infections include low fever (less than 102 F), coughing up some mucus, tiredness and muscle aches. Severe viral infection signs and symptoms may include persistent cough, short of breath, severe chest pain and weakness, coughing up blood, vomiting, dehydration, unable to eat or drink. Severe infections of some viruses like Influenza A type H1N1 may cause death in some patients.
Causes of most viral pneumonias can be Influenza A and B, Respiratory syncytial virus (RSV, usually in children), Adenovirus, Parainfluenza and rarely, Varicella viruses. Occasionally, outbreaks occur with other viruses.
Viral Pneumonia Symptoms
Most viral pneumonias have the following symptoms in common:
- Low-grade fever (less than 102 F)
- Coughing up small amounts of mucus
- Muscle aches
Symptoms of pneumonia caused by a virus other than influenza usually go on for several days to a few weeks before you call your doctor. Most people with bacterial pneumonia and influenza get sick very quickly and see a doctor within a few days.
Viral Pneumonia Causes
Viral pneumonia can be caused by influenza virus, respiratory syncytial virus (RSV), and the herpes or varicella viruses as well as those that cause the common cold (parainfluenza, coronaviruses, and adenoviruses).
Depending on which virus is involved, the symptoms and severity and treatment varies.
- 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 decreases significantly (but is not totally prevented) if you get immunized ("flu shot") every year.
- Respiratory syncytial virus (RSV) is most common in the spring. It usually infects children and can cause outbreaks in day-care centers and hospital nurseries.
- Herpes, or varicella, pneumonia is rare unless you are infected with chickenpox. This tends to be a more common complication in adults who get chickenpox.
- Adenovirus and parainfluenza viral pneumonias are often accompanied by cold symptoms such as runny nose and pinkeye (conjunctivitis).
The body’s respiratory system includes the nose, sinuses, mouth, throat (pharynx), voice box (larynx), windpipe (trachea), and lungs. Upper respiratory infections affect the parts of the respiratory tract that are higher on the body, including the nose, sinuses, and throat, while lower respiratory infections affect the airways and lungs.
Upper Respiratory Infection
Types of upper respiratory infection include the common cold (head cold), the flu, tonsillitis, laryngitis, and sinus infection. Of the upper respiratory infection symptoms, the most common is a cough. Other symptoms of upper respiratory infection may include stuffy or runny nose, sore throat, sneezing, muscle aches, and headache.
Lower Respiratory Infection
Lower respiratory infection can be caused by bronchitis, pneumonia, respiratory syncytial virus (RSV), severe flu, or tuberculosis, for example). Lower respiratory infection symptoms include a severe cough that may produce mucus (phlegm), cause shortness of breath, chest tightness, and wheezing when exhaling.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.